Protection

PSS®SINCAL 6.5

Protection Coordination

Protection Coordination in Electricity Networks

Published by SIEMENS AG Freyeslebenstraße 1, 91058 Erlangen E D SE PTI SW

SIEMENS PSS SINCAL Protection Coordination Manual

Preface

PSS® is a registered trademark of SIEMENS AG

Copyright SIEMENS AG 2009 All Rights Reserved

Preface

The PSS SINCAL manuals can be divided into three parts:

● the PSS SINCAL System Manual

● technical manuals for electricity and flow networks

● the database description

The user can find the general principles for using the PSS SINCAL manual and the PSS SINCAL

user interface in the PSS SINCAL System Manual.

The technical manuals for electricity networks contain detailed descriptions of the various

calculation methods for electricity networks - such as load flow, or short circuit calculations - and

their input data.

The technical manuals for pipe networks contain detailed descriptions of the various calculation

methods for pipe networks - water, gas and heating - and their input data.

The database description contains a complete description of the data models for electricity and

flow networks.

Copyright

This manual and all the information and illustrations contained in it are copyrighted.

SIEMENS retains all rights, in particular the right to publish, translate, reprint, photocopy, make

microcopies or electronically store in a database.

Previously expressed written permission from SIEMENS is required for any reproduction or use

beyond the limits specified by copyright law.

Warranty

Even though our manuals are thoroughly checked for errors, no liability can be taken for errors

found or any resulting problems or difficulties. Modifications are frequently made to the text and the

software as a part of our routine updates.


Table of Contents

April 2010

1. Introduction to Protection Coordination 1

2. Protection Simulation 4

2.1 OC Protection Devices 9

2.1.1 Pickup OC Protection Devices 9

2.1.2 Characteristic-Curve Tripping 12

2.1.3 First Instantaneous Tripping 14

2.1.4 Second instantaneous Tripping 14

2.1.5 Third Instantaneous Tripping 15

2.1.6 Measurement Transformer Influence 16

2.1.7 Composition of the Characteristic Curve 17

2.1.8 Determining Intersection for Double Logarithmic Coordinates 18

2.1.9 Determining the State of Protection Devices 19

2.1.10 Graphic Display with Diagrams 20

2.1.11 Graphic Display with Legends 22

2.1.12 Importing and Exporting Protection Device Settings 22

2.2 Types of OC Protection Devices 25

2.2.1 Creating a New OC Protection Device Type 25

2.2.2 Editing OC Protection Device Types 25

2.2.3 Creating and Configuring OC Protection Device Types 28

2.2.4 Copying OC Protection Device Types 29

2.2.5 Configuring OC Protection Device Types 30

2.2.6 Assigning the OC Protection Device Type 43

2.3 Distance-Protection Devices 44

2.3.1 Shapes of Impedance Areas 44

2.3.2 Pickup Distance Protection Devices 47

2.3.3 Tripping with Distance Protection Devices 49

2.3.4 Measurement Transformer Influence 49

2.3.5 Impedance Loops 50

2.3.6 Determining the State of Distance-Protection Device 53

2.3.7 PSS SINCAL Diagrams 53

2.4 Differential Protection Devices 55

PSS SINCAL Protection Coordination Manual SIEMENS

Table of Contents

April 2010

2.4.1 Protection Zone 55

2.5 Teleprotection 56

2.5.1 Signals at OC Protection Devices 57

2.5.2 Signals at Distance Protection Devices 57

2.5.3 Example for Blocked Tripping 58

2.6 Determining Tripping and Waiting Times for Protection Devices 59

2.6.1 Sequence to Determine Times 60

2.6.2 Determining Clearing Times for Faults 61

2.6.3 Distance Protection Tripping due to Phase-Fault Setting 61

2.6.4 Distance Protection Tripping due to Ground-Fault Setting 61

2.6.5 Distance Protection Tripping for Load Current 62

2.7 Recommendations and Warnings 62

3. Protection Routes 63

4. Protection Device Settings 66

4.1 Supported Protection Device Types 67

4.1.1 How Distance Protection Devices Work 69

4.1.2 Circular Tripping Areas 70

4.1.3 Quadrilateral-Shaped Tripping Areas 70

4.1.4 Common 71

4.1.5 7SA500, 7SA501 and 7SA502 72

4.1.6 7SA510, 7SA511 and 7SA513 73

4.1.7 7SA522 74

4.1.8 7SA610, 7SA611, 7SA612, 7SA631 and 7SA632 75

4.1.9 7SL13 76

4.1.10 7SL17, 7SL24, 7SL70 and 7SL73 77

4.1.11 EPAC3100, EPAC3400, EPAC3500, EPAC3600 and EPAC3700 78

4.1.12 LZ91 and LZ92 79

4.1.13 PD531 and PD551 80

4.1.14 PD532 and PD552 81

4.1.15 R1KZ4, R1KZ4A, RK4 and RK4A 82

4.1.16 R1KZ7 and R1KZ7G 83


Table of Contents

April 2010

4.1.17 R1Z25, R1Z25A and R1Z23B 84

4.1.18 R1Z27 85

4.1.19 RD10 86

4.1.20 REL316 87

4.1.21 REL521 and REL561 88

4.1.22 SD124 89

4.1.23 SD135 90

4.1.24 SD135A 91

4.1.25 SD14, SD14A and SD14B 92

4.1.26 SD34A 93

4.1.27 SD35 94

4.1.28 SD35A and SD35C 95

4.1.29 SD36 96

4.2 Calculation Method 97

4.2.1 Entries for Determining Impedance 97

4.2.2 Type of Measurement 103

4.2.3 Selective Grading Factors 109

4.2.4 DISTAL Strategy 110

4.2.5 Line Impedance Strategy 115

4.2.6 Line Impedance Strategy Connected 117

4.2.7 Medium-Voltage Network Strategy 117

4.3 Results of Settings Calculations 120

4.4 Hints and Cautions 121

5. Fault Detection 122

6. Dimensioning 124

6.1 Calculation Methods 125

7. Examples 132

7.1 Example for Protection Coordination 132

7.1.1 Presetting Calculation Settings 133

7.1.2 Creating Protection Devices 133


Table of Contents

April 2010

7.1.3 Making Fault Observations 136

7.1.4 Making Fault Events 137

7.1.5 Determining Settings for DI Protection Devices 138

7.1.6 Checking Tripping Behavior for Protection Devices 141

7.1.7 Starting the Protection Simulation 141

7.1.8 Displaying and Evaluating the Results 142

7.1.9 Generating Protection-Route Diagrams 144

7.2 Example for Creating Protection Documentation 145

7.2.1 Selecting Grading 146

7.2.2 Creating the Protection Documentation 147

7.2.3 Inserting a Diagram 148


Introduction to Protection Coordination

April 2010 1

1. Introduction to Protection Coordination

Faults can never be prevented completely in electrical transmission and distribution networks.

PSS SINCAL Protection Coordination, however, has been designed to limit most of the effects of

faults to assure continued operation of the network.

The main goals of PSS SINCAL Protection Coordination are:

● To keep the network operational

When there is a fault, you want to shut down only a minimum amount of equipment to isolate

the fault.

● To prevent the problem from spreading

When there is a fault, a lack of selectivity or overloading can cause the problem to spread.

● To protect the main equipment of the network

Your priority is protecting the most important and most expensive equipment in the network

(generators, transformers, etc.) from the fault.

PSS SINCAL Protection Coordination offers a wide range of procedures covering the complex field

of protecting or examining electrical transmission and distribution networks.

This manual contains the following chapters:

● Protection Simulation

● Protection Routes

● Protection Device Settings

● Fault Detection

● Dimensioning

● Examples

Protection Simulation

PSS SINCAL Protection Simulation calculates the amount of current, voltage, power and

impedance in case of

● One-phase to ground,

● Two-phase to ground,

● Two-phase short circuit and

● Three-phase short circuit

and links these to the setting for the protection device. Calculations are based on VDE or IEC

specifications. Simultaneously, PSS SINCAL accounts for initial load conditions.

Currents from short circuit calculations and the calculated impedances are then used to determine

the pickup protection devices.

Generating Diagrams of Protection Routes

PSS SINCAL can generate protection-route diagrams so that you can check that protection devices

have been set properly.



April 2010 2

Determining Settings for Protection Devices

This simulation procedure determines how distance protection devices are set. The various types

of protection-device types in the network and their selective grading factors are used to calculate

the values actually set at the protection device.

Detecting Faults

PSS SINCAL fault detection lets you locate a fault in the supply network. PSS SINCAL calculates

this position from the values registered at the protection device at the moment the fault takes place.

Dimensioning

Low-Voltage Dimensioning calculates minimum one-phase short circuit currents in low voltage

networks. Load flow is determined in the load flow part of the program; minimum one-phase short

circuit current is determined in the short circuit part of the program. The user must keep in mind

that the rated fuse current must be larger than the load current yet smaller than the minimum

permissible one-phase short circuit current in fuse records. PSS SINCAL shows the user any

possible discrepancies in the VDE safeguards.

Protection Coordination Procedure

To process protection coordination or create special data for the protection coordination, the

Calculation Method for Protection Device Coordination must first be switched ON.

The following steps are necessary:

● Create and define the tripping behavior of protection devices

● Define the arc reserve to determine the settings in the network level data

● Create fault observations

Network Calculations

The speed with which network calculations can be made depends primarily on five factors:

● Network size

● Number of regulated elements

● Calculation type

● Available storage capacity

Using Load Flow to Determine Load Voltage

Before protection can be simulated, PSS SINCAL calculates the load flow to determine load

voltage. One reason is that PSS SINCAL needs this load voltage to determine the direction in the

protection simulation.

Determining Permanent Load Currents from Load Flow

Sometimes networks are displayed on a computer in such a way that the load flow problem is not

solvable.



April 2010 3

Displaying the Networks for the Calculations

For a detailed description of how the networks are displayed for the calculations, see the chapter

Network Display in the Input Data Manual.

Definitions

Overcurrent Time Protection

PSS SINCAL Overcurrent Time Protection uses current as the criterion of protection, assuring that

the maximum operating current for the equipment is not exceeded for a long period of time. This

protects the network from thermal overloading, from fault currents and from excessive operating

currents.

In this manual, overcurrent time protection devices will also be called OC protection devices.

Distance Protection

PSS SINCAL distance protection determines the distance from the protection device to the fault

location indirectly from the line impedance. The criterion of distance protection is impedance.

PSS SINCAL determines impedance by measuring the current and voltage at the ends of the

equipment to be protected. The amount of impedance is closer to the fault.

Selectivity

PSS SINCAL can detect a fault in the network and shut it off with minimum repercussions to the

network as a whole.



April 2010 4

2. Protection Simulation

PSS SINCAL Protection Simulation can be used to simulate electrical networks with serial and

cross admittance, source voltages for generators, tripping characteristics for protection devices,

and permissible short circuit currents for the equipment. These devices determine the maximum

short circuit currents. PSS SINCAL searches for tripping sequences and times for protection

devices when the network has overcurrents. PSS SINCAL can also simulate, at arbitrary

intersection nodes or in lines, overcurrents caused by short circuits.

PSS SINCAL Short Circuit calculates overcurrents with referred impedance (reference power 1

MVA) and uses symmetrical components to calculate one-phase faults.

General Remarks to Protection Simulation

PSS SINCAL can easily simulate a wide variety of problems in day-to-day network operations. The

range of applications is not limited to the specific problems and needs of network operators.

Like other PSS SINCAL calculation procedures, PSS SINCAL Overcurrent Protection can calculate

the following types of networks in a single operation:

● Utility and industrial networks

● Meshed and/or radial networks

● Medium- and low-voltage networks

● Networks with several voltage levels

● Subnetworks with separate supply

PSS SINCAL Short Circuit calculates short circuit currents. PSS SINCAL Protection Simulation

examines the following kinds of faults:

● One-phase to ground

● Two-phase to ground

● Two-phase short circuit

● Three-phase short circuit

● Currents with and without initial load

● Currents involving line couplings in the zero-phase-sequence

● Currents involving a neutrally connected transformer in the zero-phase-sequence

PSS SINCAL Protection Simulation can:

● Observe various types of protection devices (overcurrent protection, distance protection)

● Define faults anywhere in nodes or lines

● Augment protection-device catalogues to meet individual needs

● Observe more than one time interval to clear the fault

● Consider directional elements with freely definable ranges in its calculations

● Consider fault impedance

● Display tripping curves for protection devices, relative to their smallest node voltage, in a

double logarithmic current-time diagram

● Display more than one subnetwork or network level in a double logarithmic current-time

diagram

● Display the impedance of more than one protection device in more than one subnetwork in the

R-X diagram



April 2010 5

● Use load current to check for tripping errors

● Display tripping characteristics, tripping currents and damage curves in a double logarithmic

current-time diagram

PSS SINCAL Protection Simulation can be used to:

● Determine fault-clearing times at any of the fault locations

● Monitor the selectivity of protection devices

● Check selective gradings for protection devices

● Verify the thermal load of the equipment

● Investigate tripping errors occurring in normal network operation



April 2010 6

Calculation Procedures for Protection Simulation

Illustration: Sequence diagram

Download and check all network data

Calculate load flow

Check, if protection devices get energized under load current

Set protection devices to "not energized" and initialize loop counter to 1

Wait for the command "continue if loop counter is greater than 1"

Generate switches for all open protection devices

Calculate fault currents, voltages and impedances

Are there any more energized protection devices?

Yes

No

Is current at fault observation equal to 0?

Yes No

Fault cannot be disconnected

Fault disconnected

Assign fault currents, voltages and impedances to protection devices

Determine opening times for protection devices

Determine states of protection devices (tripped, energized, inactive)



April 2010 7

Protection Devices

PSS SINCAL Protection Simulation recognizes the following kinds of protection devices:

OC Protection Devices

● Circuit Breakers with Measurement Transformers

● Low-Voltage Circuit Breakers

● Fuses

● Bi-Metallic Circuit Breakers

● Contactors

● Trip Fuses

Distance Protection Devices

● Distance Protection Devices

Differential Protection Devices

● Differential Protection Devices

PSS SINCAL can simulate these protection devices at any of the network elements.

Available Protection Devices in Protection Simulation

In the current version, PSS SINCAL component protection simulation recognizes only the following

types of components:

● All OC protection devices

● Distance protection devices

Checking Load Energizing

Because of the different load conditions, PSS SINCAL increases the current by a safety margin or

reduces the impedance by a safety margin when it checks energizing from the load current. For

network level data, these safety parameters are set in the Protection tab.

OC Protection Devices

PSS SINCAL calculates the load current margin as follows to check the energizing:

0,100

f0,1II Ilfprf

If the resulting test current passes through the protection device’s current-time curve, the load is

energized.



April 2010 8

Distance Protection Devices

PSS SINCAL reduces loop impedances from load voltage and load current as follows:

0,100

f0,1ZZ Z

lfprf

PSS SINCAL uses an angle to create the following test impedance area from impedance and

reduced loop impedance.

Illustration: Test impedance area for load energizing

If the test impedance area superimposes a protection device’s tripping area, the load is energized.

Energizing

The check PSS SINCAL makes depends on the type of the energizing. For current energizing

without tripping, or in directional and non-directional current energizing, PSS SINCAL uses the

admitted load current. For area energizing, PSS SINCAL uses the test impedance area.

X

R

+

Zlf

-

Zprf



April 2010 9

2.1 OC Protection Devices

Each OC protection device has a characteristic curve made up of segments. Segments can be

combined to create tripping characteristics for any type of protection device. Individual segments

are active or inactive, depending on the type of protection device. PSS SINCAL Protection

Simulation recognizes the following type of OC protection device.

● Circuit breakers with measurement transformers

● Low-voltage circuit breakers

● Fuses

● Bi-metallic circuit breakers

● Contactors

● Trip fuses

All protection devices will trip if the current through the protection device crosses the tripping curve

of the protection device. PSS SINCAL recreates the characteristic tripping curve for all OC

protection devices in the same way.

Characteristics

All protection devices have a segmented tripping characteristic curve. Individual segments are

assigned separate tripping characteristics for phase and ground faults as follows:

● Characteristic-curve tripping

● First instantaneous tripping

● Second instantaneous tripping

● Third instantaneous tripping

PSS SINCAL automatically specifies the individual segments of the characteristic curve depending

on the type of protection device. Switches can be used to deactivate individual segments.

If the protection device is connected to the network via measurement transformer, the following can

also influence how the device trips:

● Rated current for the primary measurement transformer

● Rated current for the secondary measurement transformer

● Incoming current at the protection device

Protection devices connected to the network via measurement transformers can also have

directional elements. In this case, the direction set for the current’s angle determines how the

device trips.

For all these options, PSS SINCAL considers directional elements, intermediate transformers,

delays, percentages, etc.

2.1.1 Pickup OC Protection Devices

Modern protection devices can have various kinds of pickup conditions:

● Current pickup

● Underimpedance pickup

● Undervoltage pickup



April 2010 10

● Impedance pickup – area pickup

Each of these conditions also has an end time. If the device has not tripped before this time, then it

trips automatically.

For a detailed description of the pickup input data, see the section on Pickup in the chapter on

Protection Coordination in the Input Data Manual.

Current Pickup

This condition is fulfilled when values drop below a minimum current. Simply going below this

current fulfills the condition.

PSS SINCAL supports three different types of current pickup:

● Directional current pickup (without tripping).

This type of pickup considers the setting for the direction (forwards, backwards). There is no

final time, so the protection device does not necessarily trip.

● Directional current pickup.

This type of pickup considers the setting for the direction (forwards, backwards).

● Non-directional current pickup

Underimpedance Pickup

Several conditions have to be fulfilled before there is underimpedance pickup.

● Exceeding the limits of minimum current I> and

● Being below the voltages V> until V>> at a current of between I> and I>>

● Exceeding the current I>>

Illustration: Current and voltage in underimpedance pickup

I

V

Inactive

Energized

V>

V>>

I> I>>



April 2010 11

Undervoltage Pickup

Falling below a minimum voltage and a minimum current fulfills the condition for this type of pickup.

Illustration: Current and voltage in undervoltage pickup

Impedance Pickup – Area Pickup

With impedance pickup, the impedance registered by the protection device must be within a

prescribed impedance area to meet the pickup condition. A SIEMENS area describes this type of

pickup.

The pickup area can be assigned two different final times (directional and non-directional).

I

V

Inactive

Energized

V>

I>



April 2010 12

2.1.2 Characteristic-Curve Tripping

The tripping characteristics are defined by a curve with double logarithmic current-time axes.

Depending on the type of protection device, current and time values are shown as:

● Absolute values (fuses)

● Standard values (bi-metallic circuit breakers, circuit breakers with transformers, etc.)

Absolute values for tripping characteristics cannot be modified. When the operator enters a

differently rated current, PSS SINCAL automatically selects other tripping characteristics.

Illustration: Tripping characteristics for fuses with different rated currents

Multiplying the settings for current or time changes the standard values for a characteristic curve,

moving the characteristic curve either horizontally or vertically in the current-time diagram. When

the operator enters different tripping characteristics, PSS SINCAL automatically selects a different

standard characteristic curve.

PSS SINCAL can display currents for standard characteristic curves:

● In amperes

● Relative to the rated current

The current for the tripping is then:

● Current = norm x setting

● Current = norm x setting x rated current

t

I

IN1 IN2



April 2010 13

PSS SINCAL always displays the time value for the tripping as:

● Norm x setting

Illustration: Standard characteristic curve for a protection device

Illustration: Standard characteristic curve with different settings for current

Illustration: Standard characteristic curve with different settings for time

t

I

I=I1 I=I2

t

I

I=I1 I=I2

t

I



April 2010 14

2.1.3 First Instantaneous Tripping

Current and time values define the first instantaneous tripping.

PSS SINCAL can display currents for the first instantaneous tripping:

● In amperes


● Relative to the setting for characteristic-curve tripping


● Current = setting

● Current = setting x rated current

● Current = setting x current for the characteristic-curve tripping

PSS SINCAL assigns a fixed tripping time for the first short circuit.

Illustration: Characteristic curve for first instantaneous tripping

2.1.4 Second instantaneous Tripping

Current and time values define the second instantaneous tripping.

PSS SINCAL can display currents for the second instantaneous tripping:

● In amperes



● Relative to the setting for the first instantaneous tripping





● Current = setting x current for the first instantaneous tripping

PSS SINCAL assigns a fixed tripping time for the second short circuit.

t

I



April 2010 15

Illustration: Characteristic curve for the second instantaneous tripping

2.1.5 Third Instantaneous Tripping

Current and time values define the third instantaneous tripping.

PSS SINCAL can display currents for the third instantaneous tripping:

● In amperes



● Relative to the setting for the first instantaneous tripping

● Relative to the setting for the second instantaneous tripping





● Current = setting x current for the first instantaneous tripping

● Current = setting x current for the second instantaneous tripping

PSS SINCAL assigns a fixed tripping time for the third short circuit.

Illustration: Characteristic curve for third instantaneous tripping

I

t

t

I



April 2010 16

2.1.6 Measurement Transformer Influence

The current through the protection device is influenced by the transmission ratio between the

measurement transformers:

● Primary and secondary rated current

If the current entering the protection device is not the same as the measurement transformer’s

secondary rated current, PSS SINCAL also has to consider the ratio between:

● The secondary rated current and the incoming current

Directional Element Settings

If there is a directional element, the preliminary settings for direction and range angle influence the

behavior of a protection device.

PSS SINCAL has the following settings for direction:

● Non-directional (current can have any angle)

● Forward (angle range towards the line)

● Reverse (angle range away from the line)

The settings for direction do not really depend on whether the current flows towards the line or

away from it. They only set the range of angles used. The current’s angle always refers to a

voltage. This can be either:

● Current voltage (voltage remaining after the short circuit)

● Voltage from the load flow (voltage stored at the protection device)

If the current voltage is zero (protection devices located directly at the fault location), PSS SINCAL

uses the voltage from the load flow.

Directional Elements, Intermediate Measurement Transformers, Delays and

Percentages

PSS SINCAL uses multipliers to consider these ratings for:

● Measurement transformers


● First instantaneous tripping

● Second instantaneous tripping

● Third instantaneous tripping



April 2010 17

2.1.7 Composition of the Characteristic Curve

Characteristic curves are made up of segments. PSS SINCAL considers only those segments that

are switched on.

Illustration: Segments of characteristic curve, first, second and third instantaneous tripping

Illustration: Characteristic curve with active curve and second instantaneous tripping

I

t

I

t

I

t

I

t

I

t



April 2010 18

Illustration: Characteristic curve with active curve, first or third instantaneous tripping

Illustration: Characteristic curve with active first and second instantaneous tripping

2.1.8 Determining Intersection for Double Logarithmic Coordinates

Linear interpolation in a double logarithmic system of coordinates produces the wrong results.

Linear interpolation assumes a linear system of coordinates.

Illustration: Double logarithmic system

Double logarithmic systems must therefore be converted to double linear systems for linear

interpolation. This is done using a base-ten logarithm. To prevent calculation errors, the results can

be multiplied by a constant factor.

Ilog

tlog

0,1

1

10

1 10 100

I

t

I

t



April 2010 19

)l(10logFIloglin

)t(10logFtloglin

Illustration: Double linear system

In this double linear system, linear interpolation can be made to find the point of intersection. The

results of the linear interpolation are then converted back to the double logarithmic system.

F

t

log

l in

10t

Direct linear interpolation in a double logarithmic system would produce an error of up to 10%.

2.1.9 Determining the State of Protection Devices

A protection device can have the following states:

● Inactive

● Picked-up

● Tripped

Inactive

A protection device is inactive if the current passing through it is less than the smallest current of

its tripping characteristics or less than the smallest current of all the instantaneous tripping. The

current passing through the protection device does not cross the tripping characteristic curve.

Picked-Up

A protection device has been picked up if the current passing through it is equal to, or greater than,

the smallest current of its tripping characteristics or is equal to, or greater than, the current of all the

instantaneous tripping. The tripping time is where the current passing through the protection device

intersects with the tripping characteristic curve. This means that all picked-up protection devices

can be assigned tripping times.

-1

0

1

0 1 2 Ilin

tlin



April 2010 20

Tripped Condition

In every simulation loop, PSS SINCAL trips the protection device that has the smallest tripping

time.

To allow for calculation errors, a safety time interval is added to the smallest tripping time.

Within this interval, all the protection devices trip. If the smallest tripping time is 150 ms and the

safety time interval is 0.5 ms, all the protection devices with tripping times less than 150.5 ms trip.

2.1.10 Graphic Display with Diagrams

PSS SINCAL provides two diagrams to display the results on the screen:

● Double logarithmic current-time diagram

● Linear R-X diagram

PSS SINCAL provides various diagram types so that settings and evaluations are easier for the

user to handle.

OC protection devices need an impedance area to be displayed as an R-X diagram. PSS SINCAL

normally uses a circle to represent this area. PSS SINCAL uses the calculated currents and

voltages at the protection device and determines the phase where the tripping current is flowing.

To determine the radius for the circle, the minimum impedance can be calculated from:

● The phase-ground loop

● Both phase-loops

Advantages of a Double Logarithmic Current-Time Diagram

● This proves the characteristic curves are unique.

● It is simple to compare these diagrams with the stair-shaped characteristic curves of distance-

protection devices.

● It shows the destruction limit.



April 2010 21

Illustration: Double logarithmic current-time diagram

Advantages of an R-X Diagram

● This is a simple way to compare the areas.

● The impedance to the fault location can be shown as a cursor.

● It enables a comparison with protection devices for distance protection.

Illustration: R-X diagram



April 2010 22

2.1.11 Graphic Display with Legends

This function lets you create your own legends for ranges and input data for individual OC

protection devices. Simply switch Insert Legend… ON in the protection device’s pop-up menu.

Illustration: Dialog box for Protection Device Legend

Use Select function to insert new legends or update existing ones.

You can insert up to two legends per protection device. They can be defined with the options for

Range and Input Data in the Insert Legend section.

Update existing Legends assigns all existing legends the settings you have entered in Options.

Use Options to define the legend’s layout (to either the right or the left of the protection device) as

well as the distances from the protection device to the legends (for range and input data).

When Use only selected protection devices is switched ON, PSS SINCAL uses all selected

settings in the dialog box only for previously selected protection devices. If this is not switched ON,

PSS SINCAL considers all the protection devices in the current view.

2.1.12 Importing and Exporting Protection Device Settings

PSS SINCAL can import or export OC protection device settings.

Importing Protection Device Settings

This function imports OC protection device settings from a DIGSI XML file. DIGSI has an

import/export interface that lets you use the DIGSI XML file to exchange protection device settings.

This file can read in protection device settings from DIGSI for use in PSS SINCAL.

Click Import Settings… in the pop-up menu of the protection device to activate this function.



April 2010 23

Illustration: Import Protection Device Settings

This opens the Import Protection Device Settings dialog box. In this dialog box the DIGSI XML

file can be selected for import.

The Import Options section specifies the group of settings from DIGSI you want to import:

● First setting:

The first setting group from the DIGSI XML file is used automatically.

● Setting group name:

This option is used to enter the name for the setting group you want to import.

When Use setting address for identification is switched ON, PSS SINCAL attempts to use the

address of the setting to assign the settings for this type of protection device. When this option is

switched OFF, PSS SINCAL uses the name of the setting to assign them.

Exporting Protection Device Settings

This function exports OC protection device settings to a DIGSI XML file. DIGSI has an

import/export interface that lets you use the DIGSI XML to exchange protection device settings.

This file can transfer protection device settings from PSS SINCAL to DIGSI.

Click Export Settings… in the pop-up menu of the protection device to switch this function ON.



April 2010 24

Illustration: Export Protection Device Settings

This opens the Export Protection Device Settings dialog box. In this dialog box the DIGSI XML

file can be defined for export. If you have selected more than one protection devices, you need to

select a directory for export.

In the Export Options section you can select between two modes.

● Create reduced file:

Only PSS SINCAL protection device settings are exported.

● Update existing file:

If a DIGSI XML file exists, PSS SINCAL protection device settings can be updated without

changing the other settings in the file.

If multiple protection devices are selected, this list of options is not available. In this case,

PSS SINCAL creates a new DIGSI XML file with the name of the protection device for each

protection device you have selected.

Finally, you can define the DIGSI setting group for export:

● First setting:

PSS SINCAL automatically uses the first setting group from the selected DIGSI XML file. This

option is only available when you update the DIGSI file.

● None:

No group of settings is created. PSS SINCAL only writes a value in the DIGSI XML file. This

option is only available when you create a new file.

● Setting group name:

This option is used to enter the name for the setting group you want to export.

When the option Use setting address for identification is switched ON, PSS SINCAL exports the

setting address to the DIGSI XML file as an attribute for assigning settings. When this option is

switched OFF, PSS SINCAL uses the name of the settings as an attribute for the assignment.



April 2010 25

2.2 Types of OC Protection Devices

PSS SINCAL uses segmented tripping characteristics to simulate the functions of OC protection

devices. The scope and the functions of these individual segments are stored in a special database

for protection device types.

This lets you recreate different OC protection device types in PSS SINCAL without any problems.

PSS SINCAL has a database for OC protection device types with approximately 2500 types. If you

cannot find the OC protection device type you need in this global database, it can also be created

and configured in a local database.

OC protection device types are divided into the following types:

● Circuit breakers with measurement transformers

● Low-voltage circuit breakers

● Fuses

● Bi-metallic circuit breakers

● Contactors

● Trip fuses

2.2.1 Creating a New OC Protection Device Type

File – Administration – New Protection Database... in the menu creates an empty protection

database that is not assigned to any network for the present (see the section on New Protection

Database in the chapter on Basic Functions). In the Options dialog box you can assign the

database.

2.2.2 Editing OC Protection Device Types

Insert – Standard Type – Overcurrent Time Protection… opens the screen form for working on

OC protection device types, if you have switched ON the calculation method for protection

coordination.



April 2010 26

Illustration: Menu for opening the screen form for an OC protection device type

Illustration: Screen form for editing OC protection device types

The screen form for editing OC protection device types has two sections:

● Browser for type selection

● Data screen area

The browser for type selection has the type selected for editing. PSS SINCAL displays all

settings for this type in the data screen area, where they can be modified.

Note: The data for global types cannot be modified since this information is a standard part of

PSS SINCAL and is maintained by Siemens. But data for local types can be modified, new types

can be added and existing types can be deleted. The copy function simplifies adding new types.



April 2010 27

Toolbar

Use the toolbar to switch important functions of the browser ON to process the types.

Create new OC protection device type

Copy selected OC protection device type

Insert copied OC protection device type

Delete selected OC protection device type

Define filter

Clicking Create new OC protection device type creates a new OC protection device type. Note

that new OC protection device types can only be created in the local protection device type

database.

Clicking Copy selected OC protection device type prepares the OC protection device type you

have selected in the browser on the clipboard so it can be inserted in the local protection device

type database.

OC protection device types copied to the clipboard with the Copy function can be inserted with

Insert copied OC protection device type to the current position in the browser (but only in the

local protection device type database).

Clicking Delete selected OC protection device type deletes the OC protection device type

selected in the browser. Only local protection device types can be deleted.

Click Define filter to define filters for limiting protection device types.

Pop-Up Menu

Click the right mouse button on an OC protection device type in the browser to display the pop-up

menu.

Illustration: Pop-up menu in the OC protection device type browser

This pop-up menu lets you edit the OC protection device type directly. The functions Expand and

Collapse open or close the tree.



April 2010 28

2.2.3 Creating and Configuring OC Protection Device Types

To create a new OC protection device type, first select the form for new type in the browser of the

local database. Then select New in the pop-up menu.

Illustration: Pop-up menu for creating a new OC protection device type

Then configure the new OC protection device type in the data screen area.

Illustration: Screen form for configuring a OC protection device type

To edit an existing OC protection device type, simply select this in the browser and change its

configuration accordingly in the data screen area.



April 2010 29

2.2.4 Copying OC Protection Device Types

When OC protection device types are very similar, it is easier just to copy them. Select the type you

want to copy in the screen form and open the pop-up menu.

Illustration: Pop-up menu for copying an OC protection device type

Select Copy in the menu and insert the OC protection device type in the local database. You need

to select the corresponding form (in this case a circuit breaker) in the browser of the local database

and open the pop-up menu.

Illustration: Pop-up menu for inserting an OC protection device type

Select Paste to copy the OC protection device type to the local database.

Before you can configure the new OC protection device type, you need to select it in the browser of

the local database.



April 2010 30

2.2.5 Configuring OC Protection Device Types

OC protection device types are configured in different screen forms according to the functionality of

the OC protection device.

Configuring General Data

You need to select the collective entry in the browser of the local database to configure the general

data.

Illustration: Screen form for configuring general data for a OC protection device type

This defines the Name of the OC protection device type. PSS SINCAL displays this later within the

legend for the network diagram. The Manufacturer and User Name are supplementary

information, and as such are not needed later.

Angle Determining sets the method used to determine the impedance angle for the direction

decision.

Rated Current (Phase) and Rated Current (Ground) are just supplementary information.



April 2010 31

Configuring a Tripping Type

Basic Data

This defines the behavior of the OC protection device for the particular segment.

Illustration: Screen form for configuring the basic data of a tripping type

Normally tripping types are made up of the type of OC protection device and the protection

behavior. The following abbreviations for individual protection behavior according to IEC 255-3 can

be found in the global protection database:

Abbrev. Protection behavior

DEF Definite-time characteristic

NOR Normal inverse characteristics

VER Very inverse characteristics

EXT Extremely inverse characteristics

LTE Long time inverse characteristics

OVO Overload characteristics

OVM Overload memory characteristics

O%% Overload characteristics with pre-load in %, where %% = 29, 40, 60, 80, 99 (= 100%)

RES Residual characteristics



April 2010 32

The following abbreviations for the individual protection behavior according to ANSI /IEEE can be

found in the global protection database:


INV Inverse (AMZ inv) characteristics

SIV Short inverse (AMZ inv) characteristics

LIV Long inverse (AMZ inv) characteristics

MIV Massive inverse (AMZ inv) characteristics

VIV Strong inverse (AMZ inv) characteristics

EIV Extremely inverse (AMZ inv) characteristics

DIV Equal inverse (AMZ inv) characteristics

I2T Quadratic inverse (AMZ inv) characteristics

The following abbreviations for bi-metallic devices and circuit breakers can be found in the global

protection database:


K or C Cold characteristics

W Warm characteristics

The following names for protection devices, whose settings depend on the secondary current

transformer, can be found in the global protection database:


…_1 1 A current transformer (e.g.. 7SJ63_1.NOR)

…_5 5 A current transformer (e.g.. 7SJ63_5.NOR)

The following names analogous to the version number in the product catalog (e.g. 3WN1.4,

3WN6.D) for the low voltage circuit breaker 3WN can be found in the global protection database.

The following names for fuses can be found in the global protection database:


VDE_100 100 A low voltage fuses according to VDE (I-t characteristics with average operating time behavior)

VDEu_... Low voltage fuses according to VDE (I-t characteristics with the fastest operating time behavior)

VDEo_... Low voltage fuses according to VDE (I-t characteristics with the slowest operating time behavior)

VDE-H_500 500 A high voltage fuses according to VDE

3N.._... Siemens low voltage fuses

3G.._… Siemens high voltage fuses



April 2010 33

Ip Section for the Segment for Characteristic-Curve Tripping

Phase Tripping and Ground Tripping determine whether the tripping type has a segment with

current/time characteristic-curve tripping for phase currents or ground currents. The following

values are available:

● None:

No characteristic-curve tripping

● In:

Characteristic-curve tripping with current related to rated transformer current

● A:

Characteristic-curve tripping with current in amperes

Phase I2t Limiting and Ground I

2t Limiting determine whether characteristic-curve tripping has

an I2t current limit. The following values are available:

● None:

No I2t current limit

● In:

I2t current limit with current related to rated transformer current

● A:

I2t current limit with current in amperes

I> Section for Segment with First Instantaneous Tripping

Phase Tripping and Ground Tripping determine whether the current tripping type has a first

instantaneous tripping for phase currents or ground currents. The following values are available:

● None:

No first instantaneous tripping

● In:

First instantaneous tripping with current related to rated transformer current

● A:

First instantaneous tripping with current in amperes

● Ip:

First instantaneous tripping with current related to the current for characteristic-curve tripping


2t Limiting determine whether the first instantaneous tripping has

an I2t current limit. The following values are available:

● None:


● In:


● A:


● Ip:

I2t current limit with current related to the current for characteristic-curve tripping



April 2010 34

I>> Section for Segment with Second Instantaneous Tripping

Phase Tripping and Ground Tripping determine whether the current tripping type has a second


● None:

No second instantaneous tripping

● In:

Second instantaneous tripping with current related to rated transformer current

● A:

Second instantaneous tripping with current in amperes

● Ip:

Second instantaneous tripping with current related to the current of the characteristic-curve

tripping

● I>:

Second instantaneous tripping with current related to the current for first instantaneous tripping


2t Limiting determine whether the second instantaneous tripping

has an I2t current limit. The following values are available:

● None:


● In:


● A:


● Ip:


● I>:

I2t current limit with current related to the current for first instantaneous tripping

I>>> Section for Segment with Third Instantaneous Tripping

Phase Tripping and Ground Tripping determine whether the current tripping type has a third


● None:

No third instantaneous tripping

● In:

Third instantaneous tripping with current related to rated transformer current

● A:

Third instantaneous tripping with current in amperes

● Ip:

Third instantaneous tripping with current related to the current for characteristic-curve tripping

● I>:

Third instantaneous tripping with current related to the current for first instantaneous tripping

● I>>:

Third instantaneous tripping with current related to the current for second instantaneous

tripping



April 2010 35


2t Limiting determine whether the third instantaneous tripping

has an I2t current limit. The following values are available:

● None:


● In:


● A:


● Ip:


● I>:

I2t current limit with current related to the current for first instantaneous tripping

● I>>:

I2t current limit with current related to the current for second instantaneous tripping

Section for Tripping Characteristics

If there is characteristic-curve tripping, the appropriate tripping characteristics need to be entered.

Enter characteristic-curve values as described in the chapter on Screen Form for Characteristics

Input.

Illustration: Dialog box for editing current/time tripping characteristics

For the tripping characteristics, select I/t Curve in the Function field.

For the Type, you normally enter IT1 or IT2. If the type contains a 1, PSS SINCAL uses these

characteristics to determine the intersecting point that has the pickup current. If the type contains a

2, PSS SINCAL displays these characteristics in the current/time diagrams of Diagram View.

Characteristic-curve tripping requires at the very least a characteristic curve for tripping with an

entry for type containing a 1.



April 2010 36

The additional name in the basic data for the characteristic curve is usually the same as the

protection behavior. There is, however, no explicit entry for this additional name.

Illustration: Fuse with an entry for two tripping characteristics

OC protection device types with K (Cold) and W (Warm) tripping have an unusual feature when

this abbreviation has also been entered in the basic data of the characteristics as an additional

name. In this case, PSS SINCAL displays both characteristic curves in the current/time diagrams of

Diagram View.



April 2010 37

Illustration: Bimetal with cold and warm tripping characteristics

Tripping Function

If characteristic curve tripping exists, enter the appropriate function for calculating tripping

characteristics. Enter the parameters for the respective function as described in the chapter on

Screen Form for Characteristics Input.

Illustration: Dialog box for editing the function for calculating tripping characteristics

For the tripping characteristics, select a value for a function, e.g. Function 1, in the Function field.



April 2010 38

Only one entry for tripping characteristics is allowed. Normally the protection behavior can be

entered under Type and Name. PSS SINCAL does not, however, have specific entries for types or

names.

Illustration: Circuit breaker (CT) with transformer and normal inverse tripping

Since the tripping characteristics calculated with this function are reference characteristics, you

have to select In (= current entry for rated transformer current) in the Ip column.

Illustration: Protection device type with Function 1 with settings

You need to enter the appropriate settings for the function you have selected.



April 2010 39

To calculate tripping characteristics, this function proceeds from the initial value I/Ip to the end value

I/Ip. The result is a factor ft, which, multiplied by the time setting value for the characteristics tripping

Tp, produces the tripping time t.

tpfTt

PSS SINCAL needs to have the tripping time in seconds. If you want to have the time at the

protection device in minutes, enter a factor of 60.0 in the function to convert from minutes to

seconds.

Function 1

3PI

I

1Pf

2P

p

t

Type Parameter

1 Parameter P1

2 Parameter P2

3 Parameter P3

20 Initial value I/Ip

21 End value I/Ip

Function 2

8P

6P

p

5P2P

p

t

7PI

I

4P

3P

I

I

ln1Pf

Type Parameter

1 Parameter P1 (60.0 to convert to seconds)

2 Parameter P2

3 Parameter P3 (initial load)

4 Parameter P4

5 Parameter P5

6 Parameter P6

7 Parameter P7

8 Parameter P8

20 Initial value I/Ip

21 End value I/Ip



April 2010 40

Settings

This defines the value ranges for entries for current and time of OC protection devices for the

particular protection function.

Illustration: Screen form for configuring value ranges

Enter value ranges for the OC protection device type as described in the chapter on Screen Form

for Characteristics Input.



April 2010 41

Illustration: Screen form for configuring a value range

This data screen form describes a setting at the OC protection device.

Name is the abbreviation for the setting in the protection device description. The Unit of the setting

is also found in the protection device description. Status is used to document a setting or switch

this ON for input in the OC protection device screen form.

Setting Address contains the setting at the protection device.

Type defines the connection between setting according to description and how it is used in

PSS SINCAL. PSS SINCAL has the following values for the configuration:

Type Function

SWp Characteristic-curve tripping phase switchable

SW> First instantaneous tripping phase switchable

SW>> Second instantaneous tripping phase switchable

SW>>> Third instantaneous tripping phase switchable

SWep Characteristic-curve tripping ground switchable

SWe> First instantaneous tripping ground switchable

SWe>> Second instantaneous tripping ground switchable

SWe>>> Third instantaneous tripping ground switchable

Ip Current characteristic-curve tripping phase

I> Current first instantaneous tripping phase

I>> Current second instantaneous tripping phase

I>>> Current third instantaneous tripping phase

Iep Current characteristic-curve tripping ground

Ie> Current first instantaneous tripping ground

Ie>> Current second instantaneous tripping ground



April 2010 42

Ie>>> Current third instantaneous tripping ground

F_Ip Factor for current characteristic-curve tripping phase

F_I> Factor for current first instantaneous tripping phase

F_I>> Factor for current second instantaneous tripping phase

F_I>>> Factor for current third instantaneous tripping phase

F_Iep Factor for current characteristic-curve tripping ground

F_Ie> Factor for current first instantaneous tripping ground

F_Ie>> Factor for current second instantaneous tripping ground

F_Ie>>> Factor for current third instantaneous tripping ground

Tp Time characteristic-curve-tripping phase

T> Time first instantaneous tripping phase

T>> Time second instantaneous tripping phase

T>>> Time third instantaneous tripping phase

Tep Time characteristic-curve-tripping ground

Te> Time first instantaneous tripping ground

Te>> Time second instantaneous tripping ground

Te>>> Time third instantaneous tripping ground

F_Tp Factor for time characteristic-curve tripping phase

F_T> Factor for time first instantaneous tripping phase

F_T>> Factor for time second instantaneous tripping phase

F_T>>> Factor for time third instantaneous tripping phase

F_Tep Factor for time characteristic-curve tripping ground

F_Te> Factor for time first instantaneous tripping ground

F_Te>> Factor for time second instantaneous tripping ground

F_Te>>> Factor for time third instantaneous tripping ground

I2Ip Current I2t limit characteristic-curve tripping phase

I2I> Current I2t limit first instantaneous tripping phase

I2I>> Current I2t limit second instantaneous tripping phase

I2I>>> Current I2t limit third instantaneous tripping phase

I2Iep Current I2t limit characteristic-curve tripping ground

I2Ie> Current I2t limit first instantaneous tripping ground

I2Ie>> Current I2t limit second instantaneous tripping ground

I2Ie>>> Current I2t limit third instantaneous tripping ground

I2TIp Time I2t limit characteristic-curve tripping phase

I2T> Time I2t limit first instantaneous tripping phase

I2T>> Time I2t limit second instantaneous tripping phase

I2T>>> Time I2t limit third instantaneous tripping phase

I2Tep Time I2t limit characteristic-curve tripping ground

I2Te> Time I2t limit first instantaneous tripping ground

I2Te>> Time I2t limit second instantaneous tripping ground



April 2010 43

I2Te>>> Time I2t limit third instantaneous tripping ground

All additional types are only for documentation and do not influence how the OC protection device

type is configured.

2.2.6 Assigning the OC Protection Device Type

Once a new OC protection device has been created, PSS SINCAL displays a screen form where

you can assign the OC protection device type. Before you can do this, you have to select Settings

in the browser for the OC protection device. Select the filter button to preselect the OC protection

device types.

Illustration: Dialog box for preselecting the OC protection device types

PSS SINCAL displays the OC protection device types you have selected as a list.

Illustration: Preselected OC protection device types

When you select a type, PSS SINCAL assigns this to the OC protection device for phase and

ground tripping. If you want to use another type for ground tripping, assign this at ground. You can

only select between the individual tripping types of OC protection devices.



April 2010 44

Illustration: Screen form for selecting the OC protection device type for ground tripping

2.3 Distance-Protection Devices

Impedance areas describe distance protection devices. Distance-protection devices trip when the

impedance registered at the protection device is within a given impedance area.

PSS SINCAL recognizes various kinds of impedance areas, from simple conductance circles to

freely definable impedance areas, so that all distance protection devices in use can be simulated.

2.3.1 Shapes of Impedance Areas

PSS SINCAL represents real protection devices with the following types of tripping areas:

● Basic areas:

Rectangular or circle

● SIEMENS

● Freely definable

Depending on the shape of the area, PSS SINCAL stipulates the following:



April 2010 45

Basic Areas

This is the simplest shape. To define a rectangular area, enter the following:

● Active resistance

● Reactive reactance

● Quadrant input:

I (first quadrant)

A (all quadrants)

Depending on the type of protection device, this area can be either a rectangle or a circle.

Illustration: Rectangular impedance area

SIEMENS Areas

These areas have the typical SIEMENS shape for distance-protection devices. To define a

SIEMENS area, enter the following:

● X+A (reactive reactance)

● X-A (reactive reactance)

● RA1 (active resistance)

● RA2 (active resistance)

● (angle)

R

X

R, X

R

X

R, X

-R, -X

Type: I Type: A



April 2010 46

SIEMENS areas always have the following shape:

Illustration: SIEMENS impedance area

Freely Definable Areas

Here the user can simulate any kind of area. Ten straight lines and four circles define an area. The

straight lines, the circles and the input sequence can be defined freely.

The straight lines pass through a point that has been defined and are at an angle to the positive R

axis. Straight lines are defined by the following:

● R (active resistance)

● X (reactive reactance)

● (angle)

Three points define circles: starting, arc and end points. Circles always begin at a starting point, go

through the arc and end points and then back to the starting point. The procedure is important

since it creates the limiting line.

Circles can be lengthened or shortened in R and X directions or rotated at an angle to the positive

R axis.

Circles are defined by

● RA (active resistance at the starting point)

● XA (reactive reactance at the starting point)

● RB (active resistance at the arc point)

● XB (reactive reactance at the arc point)

● RE (active resistance at the end point)

● XE (reactive reactance at the end point)

● FR (factor for distortion in direction R)

● FX (factor for distortion in direction X)

● (angle for rotation)

R

X

X+A

X-A

RA1

RA2

-RA1

-RA2



April 2010 47

Illustration: Example of a freely defined impedance area limited by two straight lines and a circle

If there are problems setting the limiting line, either:

● Change the beginning and end point

● Change the element sequence

2.3.2 Pickup Distance Protection Devices

Modern protection devices can have various kinds of pickup conditions:

● Current pickup

● Underimpedance pickup

● Undervoltage pickup

● Impedance pickup – area pickup

Each of these conditions also has an end time. If the device has not tripped before this time, then it

trips automatically.

For a detailed description of the pickup input data, see the section on Pickup in the chapter on

Protection Coordination in the Input Data Manual.

Current Pickup

This condition is fulfilled when values drop below a minimum current. Simply going below this

current fulfills the condition.

PSS SINCAL supports three different types of current pickup:

● Directional current pickup (without tripping):

This type of pickup considers the setting for the direction (forwards, backwards). There is no

final time, so the protection device does not necessarily trip.

● Directional current pickup:

This type of pickup considers the setting for the direction (forwards, backwards).

● Non-directional current pickup

R

X

K1

G2

G1



April 2010 48

Underimpedance Pickup

Several conditions have to be fulfilled before there is underimpedance pickup.

● Exceeding the limits of minimum current I> and

● Being below the voltages V> until V>> at a current of between I> and I>>

● Exceeding the current I>>

Illustration: Current and voltage in underimpedance pickup

Undervoltage Pickup

Falling below a minimum voltage and a minimum current fulfills the condition for this type of pickup.

Illustration: Current and voltage in undervoltage pickup

Impedance Pickup – Area Pickup

With impedance pickup, the impedance registered by the protection device must be within a

prescribed impedance area to meet the pickup condition. A SIEMENS area describes this type of

pickup.

I

V

Inactive

Energized

V>

I>

I

V

Inactive

Energized

V>

V>>

I> I>>



April 2010 49

The pickup area can be assigned two different final times (directional and non-directional).

2.3.3 Tripping with Distance Protection Devices

In all kinds of tripping, the registered impedance of the protection device must be within a

prescribed impedance area.

Individual protection devices are assigned all kinds of areas with times for tripping.

To determine tripping behavior, PSS SINCAL sorts all areas of a protection device according to

tripping times (registered impedance within the area).

Illustration: Constructing areas for a protection device

All areas are sorted by times (in ascending order), independent of their shape. This assures that

the area that can trip fastest is always checked first and can trip.

2.3.4 Measurement Transformer Influence

Current and voltage transformers supply individual distance-protection devices with data.

All protection devices measure impedance either on:

● The primary side

● The secondary side

Measurement – Primary Side

Currents and voltages are not converted.

Measurement – Secondary Side

All currents are assigned this transmission ratio:

● Rated current primary/rated current secondary times

● Factor for intermediate-current transformers

R

X

t1

t2

t

R

X

R

X

t3



April 2010 50

All voltages are assigned this transmission ratio:

● Rated voltage primary/rated voltage secondary times

● Factor for intermediate-voltage transformers

Considering Directional Elements

The angle of the impedance registered for directional elements needs to be checked before

checking whether the registered impedance is inside an area.

Depending on the direction, the angle must be within its own angle range.

PSS SINCAL accepts the following settings for the direction:

● Non-directional (angle range the same)

● Forward (angle range towards the line)

● Reverse (angle range back from the line)

The setting for the direction determines in which angle range the impedance must be picked up.

The impedance angle always refers to a voltage. This voltage comprises the following parts:

… Current voltage (remaining voltage from short circuit)

… Voltage from load flow (voltage stored at the protection device)

… Voltage outside the fault (all phase voltage not affecting by the fault) rotated 90 °

A percentage can be set for all the parts. The voltage determining the angle, however, is always

the sum of all parts evaluated and comes, for example, from

fLa V%0V%0V%100

or

fLa V%20V%20V%100

The sum of the percentages does not have to be 100%!

2.3.5 Impedance Loops

The way the following impedance loops are treated differs for rectangular, SIEMENS or freely

defined impedance areas.

● Phase 1 – ground



● Phase 1 – phase 2



aV

LV

fV



April 2010 51

In rectangular impedance-areas, all impedances for all impedance loops are checked.

In SIEMENS or freely defined impedance areas, all impedance loops to be checked must be

defined. PSS SINCAL only considers impedances from active impedance loops.

Determining Impedance

The impedances of phase-phase loops have the reference

)II(jX)II(RVV21L21L21



After these have been converted, PSS SINCAL shows the active resistances (R12, R23, R31) and

reactive reactances (X 12, X 23, X31) for the protection device.

221

221

2121212112

)IIIm()IIRe(

)VVIm()IIIm()VVRe()IIRe(R

221

221

2121212112

)IIIm()IIRe(

)VVRe()IIIm()VVIm()IIRe(X

232

232

3232323223

)IIIm()IIRe(


232

232

3232323223

)IIIm()IIRe(


213

213

1313131331

)IIIm()IIRe(


213

213

1313131331

)IIIm()IIRe(


The impedances of phase-ground loops have the references

L

eL

L

eLeLL11

X

XjX

R

RRI)jXR(IV



April 2010 52

L

eL

L

eLeLL22

X

XjX

R

RRI)jXR(IV

L

eL

L

eLeLL33

X

XjX

R

RRI)jXR(IV

After they have been converted, PSS SINCAL shows the active resistances (R1e, R2e, R3e) and

reactive reactances (X 1e, X 2e, X3e) for the protection device.

L

ee1

L

ee1

L

ee1

L

ee1

1

L

ee11

L

ee1

e1

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VIm(X

XIIIm)VRe(

X

XIIRe

R

L

ee1

L

ee1

L

ee1

L

ee1

1

L

ee11

L

ee1

e1

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VRe(R

RIIIm)VIm(

R

RIIRe

X

L

ee2

L

ee2

L

ee2

L

ee2

2

L

ee22

L

ee2

e2

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VIm(X

XIIIm)VRe(

X

XIIRe

R

L

ee2

L

ee2

L

ee2

L

ee2

2

L

ee22

L

ee2

e2

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VRe(R

RIIIm)VIm(

R

RIIRe

X

L

ee3

L

ee3

L

ee3

L

ee3

3

L

ee33

L

ee3

e3

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VIm(X

XIIIm)VRe(

X

XIIRe

R

L

ee3

L

ee3

L

ee3

L

ee3

3

L

ee33

L

ee3

e3

X

XIIIm

R

RIIIm

X

XIIRe

R

RIIRe

)VRe(R

RIIIm)VIm(

R

RIIRe

X

The following references must be set at the protection device.



April 2010 53

L

e

L

e

X

Xand

R

R

2.3.6 Determining the State of Distance-Protection Device

Distance-protection devices can have the following states:

● Inactive

● Picked-up

● Tripped

Because of the signal locks, protection devices that have already been tripped must be considered

in the future clearing procedure.

Inactive

A distance-protection device is inactive if none of the pickup conditions are fulfilled.

When no pickup conditions have been set, the impedance registered by the distance-protection

device must be outside all impedance areas for the protection device to be inactive.

Picked-up

A distance-protection device has been picked up if one of the pickup conditions is fulfilled.

When no pickup conditions have been set, the registered impedance of the distance-protection

device must be inside at least one impedance area for the protection device to be picked up.

Tripped

In every simulation loop, the protection device with the smallest tripping time (either a distance

protection device or OC device) is considered tripped.

To allow for calculation errors, a safety time interval is added to the smallest tripping time.

All protection devices within this interval trip. If the smallest tripping time is 150 ms and the safety

time interval is 0.5 ms, all the protection devices with tripping times less than 150.5 ms trip.

2.3.7 PSS SINCAL Diagrams

PSS SINCAL has two types of diagram to display the results on the screen:

● Double logarithmic current-time diagram

● Linear R-X diagram

PSS SINCAL provides various diagram types so that settings and evaluations are easier for the

user to handle.

Current-time coordinates must be calculated from the impedance areas to a protection device to be

displayed in the double logarithmic current-time diagram.



April 2010 54

A loop passing through all impedance areas, and sorted according to tripping times, determines

these coordinates as follows:

● PSS SINCAL determines the impedance at the intersection of the straight lines and the limit of

the impedance area

SpZimpedance

● The present current and the impedance registered are the impedance current

Sp

trip

tripSpZ

ZII

● The tripping time for the current impedance is the same as the time tSp when the current ISp also

trips. A pair of coordinates for the double logarithmic current-time diagram has been calculated

completely.

These current-time coordinates in the double logarithmic current-time diagram are stair-shaped.

Advantages of an R-X Diagram

● This is a simple way to compare the areas.

● The impedance up to the fault location is displayed as an arrow.

● They can be compared with OC protection devices.

Illustration: R-X diagram



April 2010 55

Advantages of a Double Logarithmic Current-Time Diagram

● This is a simple way to compare these with the characteristic curves of distance-protection

devices.

● It shows the destruction limit.

Illustration: Double logarithmic current-time diagram

2.4 Differential Protection Devices

In the current PSS SINCAL version, differential protection devices are used only to limit protection

zones in reliability calculations.

Special Shape for Entering Differential Protection Devices

Entering a differential protection group lets you use OC and distance protection devices to limit the

protection zone.

2.4.1 Protection Zone

To limit a protection zone, the topology of the protection device and the differential protection group

are necessary. Depending on the entry, PSS SINCAL has the following protection zones:

Differential Protection for Nodes or Busbars

All differential protection devices in a differential protection group must have the same insert node.

In PSS SINCAL, however, not all the node or busbar connections need a protection device. Only

one device is necessary to define the differential protection zone.



April 2010 56

Differential Protection for Elements

All differential protection devices in a differential protection group must be placed at the same

network element.

Differential Protection for Fields

Differential protection devices in a differential protection group must comprise an entire network

area. These devices are placed at different elements in different nodes.

2.5 Teleprotection

In the real world, signal lines connect OC and distance-protection devices. Signals from other

protection devices therefore can keep individual protection devices from pickup.

There is no limit to the number of ways protection devices can block each other.

● OC protection device – OC protection device

● OC protection device – distance-protection device

● Distance-protection device – OC protection device

● Distance-protection device – distance-protection device

There is no limit to the number of signals, either. The following types of signals can be used to

block protection devices.

● Activated: signal picked up

● Deactivated: signal inactive

Pickup is blocked when one or more signals prevent pickup. To define a signal for blocking, the

following must be entered:

Protection Device Receiving the Signal (Protection Device 1)

● Key – protection device 1

● Zone name for condition

● Tripping for zone to be locked (phase or ground)

Protection Device Sending the Signal (Protection Device 2)

● Key – protection device 2

● Zone name

● Tripping for condition (phase or ground)

● Type of signal

Note: This only prevents the respective unit or area from being picked up.



April 2010 57

2.5.1 Signals at OC Protection Devices

A signal (picked-up or inactive) is sent to each OC protection device for the phase and ground

setting at each tripping unit. If signals are blocked, PSS SINCAL treats a tripping unit at an

overcurrent protection device like a zone for a distance protection device. PSS SINCAL has the

following tripping units:


● First short circuit current tripping

● Second short circuit current tripping

● Third short circuit current tripping

Note: With OC protection devices, all tripping units always produce a signal as follows:

● Current tripping units (phase and ground) send the signal PICKED-UP.

● Units with smaller tripping time (reserve protection for phase and ground) also send the signal

PICKED-UP.

● Units with higher tripping time or inactive units send the signal INACTIVE.

OC protection devices with PICKED-UP characteristic-curve tripping and second short circuit

current tripping send the following signals in second short circuit current tripping as an active

tripping unit:

● Characteristic-curve tripping: PICKED-UP

● First short circuit current tripping: INACTIVE

● Second short circuit current tripping: PICKED-UP

● Third short circuit current tripping: INACTIVE

Note: OC protection devices tripping in one time step do not have any current in the following time

steps. All tripping units of tripped OC protection devices therefore must always send the signal

INACTIVE in the following time steps.

2.5.2 Signals at Distance Protection Devices

Each distance-protection device has a signal (picked-up/inactive) for phase and ground setting in

each tripping area. PSS SINCAL has the following kinds of levels:

● FIRST LEVEL

● SECOND LEVEL

● THIRD LEVEL

● Pickup (impedance pickup – pickup area)

● SIEMENS areas:

Identified by the area name

● Freely definable areas:

Identified by the area name

The tripping area and the impedance the protection device registers determine which tripping area

produces which signals. PICKED-UP protection devices react to the following criteria:

● Impedance registered within the tripping area – valid direction:

PICKED-UP



April 2010 58

● Impedance registered within the tripping area – invalid direction:

INACTIVE

● Impedance registered outside the tripping area:

INACTIVE

All tripping areas for inactive protection devices send the signal INACTIVE.

Note: Distance-protection devices tripping in one time step do not have any current in the following

time steps and consequently do not register impedance. All tripping units of tripped distance-

protection devices therefore always send the signal INACTIVE in the following time steps:

2.5.3 Example for Blocked Tripping

Signals should ideally be blocked to trip faults in the first line to be protected. For reasons of

simplification, this example shows a purely Ohmic line with a resistance of three Ohms.

Illustration: Line with protection devices

Individual impedance areas register at different distances into the line. In this example, the

following is true for both protection devices:

Ohm2R1

Ohm05.3RB1

Ohm4R2

The fault occurs at a distance of 2.5 Ohm. The signal for the stipulated tripping level R1B, t1B is

always the tripping level R1, t1 of the protection device located opposite.

Illustration: Range of tripping areas

t

K1

R2, t2

K2

R2, t2

R1, t1 R1, t1 R1B, t1B R1B, t1B

SG2 SG1

SG1 SG2

K1 SG1

R=3 Ohm

SG2 K2



April 2010 59

Illustration: Signal behavior

Illustration: Protection devices with tripping times

In our example, the protection device’s switching time must be greater than:

1B1ttt

2.6 Determining Tripping and Waiting Times for Protection Devices

Calculations for the tripping time of a protection device do not depend on the type of protection

device. The following times are considered in the calculations:

Waiting Time

time from when the fault was encountered until the protection device was picked-up

Imaginary Waiting Time

waiting time calculated due to peculiarities in the algorithm to calculate the tripping time and waiting

time for a protection device

Present Tripping Time

protection device tripping time determined from existing currents and voltages

Previous Fault-Clearing Time

clearing time for final calculations

K1 K2

Clearing time of the fault: t1B

t1B t1

SG1 SG2

t

K1 K2

R1, t1 R1B, t1B

SG2 SG1

Signal of SG2 and

level R1, t1 = ENERGIZED

SG1 SG2



April 2010 60

Present Fault-Clearing Time

clearing time for present calculations

2.6.1 Sequence to Determine Times

The time is determined as follows:

Tripping Conditions for Phase Faults

● Values – phase 1



Tripping Conditions for Ground Faults




The tripping times are calculated as follows:

● The tripping time is calculated from setting ranges and phases

● If the tripping range changes for OC protection devices (characteristic-curve tripping, first short

circuit current tripping)

set the previous status of the protection device to inactive

● If the previous status is inactive

set the waiting time the same as the previous clearing time

● If the previous status is picked-up

and the tripping time is less than previous clearing time

– there is immediate tripping for an electronic protection device

– there is delayed tripping for a conventional protection device

● Calculate the present tripping time

add up the waiting time, present tripping time and imaginary waiting time

● Compare this with the clearing time for all previous setting ranges and phases

use the smallest time for each protection device

This algorithm can, however, create a problem with immediate or a delayed tripping.

The present clearing time can be smaller than the previous clearing time. Since, however, this is

impossible, the protection device must be given an imaginary waiting time.

Immediate Tripping

The imaginary waiting time for the protection device is the previous clearing time minus the present

tripping time.



April 2010 61

Delayed Tripping

The imaginary waiting time must consider the effects of heat from the new current on the protection

device. Differentiation must be made between the following two cases:

● Tripping time for the current from 1000.0 to 0.3 seconds

The 0.3 seconds must be effectively run out before the protection device trips.

● Tripping time for the current from 0.7 to 0.3 seconds

The tripping time for the current is between 0.3 and 0.7 seconds.

As can be seen in both cases, the algorithm for delayed tripping must consider both the previous

time and the previous current.

2.6.2 Determining Clearing Times for Faults

PSS SINCAL calculates clearing times for faults as follows:

● PSS SINCAL makes these clearing times equal to the smallest tripping time of all other

protection devices in the present simulation loop.

PSS SINCAL stops protection calculations automatically if:

● There are no more picked-up protection devices

● Current at the fault location is equal to zero

2.6.3 Distance Protection Tripping due to Phase-Fault Setting

For phase-fault tripping, all currents in all phases are used to fulfill the tripping conditions. The

currents in the three phases do not need to be the same size.

To fulfill the phase-tripping conditions, the current for each phase is observed separately.

The tripping conditions for the phase faults are always checked separately from the actual faults in

the network.

2.6.4 Distance Protection Tripping due to Ground-Fault Setting

Ground tripping occurs only when a ground current that does not equal zero is produced right at

the protection device. The ground current is determined from

321eIIII

The current through the protection device is different in all three phases. To fulfill the ground-

tripping conditions, the current for each phase is observed separately.

Ground-fault currents can also cause tripping due to phase-fault settings, so the characteristics for

either the phase or ground can pickup the protection device.



April 2010 62

PSS SINCAL uses the minimum value from the following to determine pickup behavior:

● Current/voltage Phase 1 and settings ground faults



● Current/voltage Phase 1 – Phase 2 and settings phase faults



2.6.5 Distance Protection Tripping for Load Current

Load current flowing through the protection device may not pickup the protection device for phase-

fault tripping.

The load flow calculations only determine the current and the voltage for Phase 1. The currents

and voltages in Phases current related to Two and Three are produced by rotating 120 or -120

degrees.

2.7 Recommendations and Warnings

The operator needs to consider the following when determining currents, times and tripping states:

● Protection devices always switch off all three phases simultaneously.

● One- or three-phase short circuit current is always determined as maximum short circuit

current. If the short circuit does not occur during crossover (null), there is less present current

and the tripping time is larger. If the damage curve of the network element crosses the tripping

curve, it can lead to heat damage and even change the tripping sequence.

● If the tripping time is greater than the previous fault-clearing time, the tripping time can be reset

so the protection devices that are already picked up do not reach maximum head load and shut

down. Otherwise, this could damage network elements and even change the tripping

sequence.

● When the safety-time interval entered is larger than the switching time, this gap produces

another current distribution for the time between the network’s switching time and safety-time

interval. This condition can alter the tripping sequence.


Protection Routes

April 2010 63

3. Protection Routes

PSS SINCAL generates various diagrams for the network and the built-in protection devices. These

diagrams are used to check the accuracy of the protection setting.

If you only create specific routes in the network as a diagram, you need to have a Network Element

Group of the type "protection route" for these elements.

Note: PSS SINCAL only generates diagrams for protection devices if these have been switched

ON in the selective grading diagram (see the section on Locating Protection Devices in the chapter

on Data Description in the Input Data Manual).

PSS SINCAL has the following diagrams:

● Tripping Behavior

● Ratio Impedances (Z)

● Ratio Reactances (X)

● Impedance and Tripping Areas

Tripping Behavior

This diagram shows the tripping behavior of protection devices over time, depending on the

impedance registered.

PSS SINCAL generates one diagram per protection route for each protection device. This diagram

also contains protection devices located in the protection route being displayed so that selective

tripping can be set and tripping times can be easily checked.

Illustration: Diagram Protection Routes – Tripping Behavior


Protection Routes

April 2010 64

Ratio Impedances (Z)

This diagram shows the impedance registered by the protection device compared to the amount of

impedance in the protection route. The tripping levels of the protection device are shown as

horizontal lines in the diagram.

PSS SINCAL generates one diagram per protection route for each protection device.

Illustration: Diagram Protection Routes – Ratio Impedances

Ratio Reactances (X)

This diagram shows the reactance registered by the protection device compared to the amount of

reactance in the protection route. The tripping levels of the protection device are shown as

horizontal lines in the diagram.



Protection Routes

April 2010 65

Illustration: Diagram Protection Routes – Ratio Reactances

Impedance and Tripping Areas

This diagram shows the impedance areas of the protection device. Impedance registered by the

protection device (at the particular node) can also help you visualize the protection route.


Illustration: Diagram Protection Routes – Impedance and Tripping Areas


Protection Device Settings

April 2010 66

4. Protection Device Settings

This simulation procedure determines the settings for distance protection devices. PSS SINCAL

calculates the values actually set at the protection device from the types of protection devices in

the network and their selective distance factors.

In addition to settings, this simulation procedure also generates diagrams as selective tripping

schedules. Larger high- and medium-voltage networks are updated all the time. This means that a

lot of effort is required to maintain the tripping plans. Formerly, second and third selective tripping

levels in meshed networks had to be calculated by hand. This meant a great deal of work and

yielded calculations that were at best approximate. Now, however, PSS SINCAL can calculate

these levels quickly and accurately.



April 2010 67

Basic Calculation Sequence for Protection Device Settings


4.1 Supported Protection Device Types

Modern distance-protection devices are like computers that trip and turn off if there is a fault, using

internal programs that measure current and voltage values and their settings.

Protection devices are so complex that they need to be simulated to understand them properly.

A special module has been integrated into PSS SINCAL protection coordination that can simulate

many kinds of distance-protection devices. Additional protection devices can easily be added to the

module.

Download and check all network data

Depending on strategy, reconstruct the network to determine settings

Loop – protection device

Set minimum impedance for limits with the help of short circuits

Have all protection devices been calculated?

No

Short circuit in new network – calculate wandering short circuit in parallel lines

Loop – steps

Calculate settings and tripping area from measurement type, type of protection device and minimum impedance

Set intersections for protection device tripping area with network resistance curve (range of protection device)

Have all steps been calculated?

Prepare results

Yes

No

Set points for limits of bends



April 2010 68

PSS SINCAL supports the following types of protection devices:

Type Function group Manufacturer

Common Common

7SA500 7SA SIEMENS

7SA501 7SA SIEMENS

7SA502 7SA SIEMENS

7SA510 7SA SIEMENS

7SA511 7SA SIEMENS

7SA513 7SA SIEMENS

7SA522 7SA SIEMENS

7SA610 7SA SIEMENS

7SA611 7SA SIEMENS

7SA612 7SA SIEMENS

7SA631 7SA SIEMENS

7SA632 7SA SIEMENS

7SL13 7SL SIEMENS

7SL17 7SL SIEMENS

7SL24 7SL SIEMENS

7SL70 7SL SIEMENS

7SL73 7SL SIEMENS

EPAC3100 PD5 ALSTOM

EPAC3400 PD5 ALSTOM

EPAC3500 PD5 ALSTOM

EPAC3600 PD5 ALSTOM

EPAC3700 PD5 ALSTOM

LZ91 LZ9

LZ92 LZ9

PD531 PD5 ALSTOM

PD532 PD5 ALSTOM

PD551 PD5 ALSTOM

PD552 PD5 ALSTOM

R1KZ4 R1KZ SIEMENS

R1KZ4A R1KZ SIEMENS

R1KZ7 R1KZ7 SIEMENS

R1KZ7G R1KZ7 SIEMENS

R1Z23B R1Z25 SIEMENS

R1Z25 R1Z25 SIEMENS

R1Z25A R1Z25 SIEMENS

R1Z27 R1Z27 SIEMENS

RD10 SD1

REL316 PD5 ABB

REL521 PD5 ABB

REL561 PD5 ABB

RK4 R1KZ SIEMENS

RK4A R1KZ SIEMENS

SD124 SD1 AEG

SD135 SD3 AEG

SD135A SD3 AEG

SD14 SD1 AEG

SD14A SD1 AEG



April 2010 69

SD14B SD1 AEG

SD34A SD34 AEG

SD35 SD3 AEG

SD35A SD3 AEG

SD35C SD3 AEG

SD36 SD36 AEG

Some 50 protection device types are divided up into 10 groups, depending on how they work.

Except for minor differences, PSS SINCAL simulates a particular group’s protection devices in the

same way.

4.1.1 How Distance Protection Devices Work

All distance protection devices work in the same way. They determine the impedances of all the

impedance loops (conductor – conductor and conductor – ground) from current and voltage in the

three-phase network.

Then PSS SINCAL checks whether the registered loop impedance is inside one or more prescribed

impedance areas. Each impedance area is assigned a constant tripping time. The constant time

per step produces jumps in the tripping time (steps) if the loop impedances registered are in

different areas.

The settings at the protection device are used as parameters for the impedance area according to

the current network. Depending on the type of protection device, impedance areas are based on

circles or impedance quadrilaterals.

All settings are secondary values at the protection device. The primary values are calculated from

the factor of the current transformer,

sec

pricurr i

Iü ,

from the factor of the voltage transformer

sec

privolt V

Vü

and from the settings.

All PSS SINCAL predefined protection device types are described below with the relevant

parameters for PSS SINCAL. Protection device types in a group have the same parameters as

used in PSS SINCAL.



April 2010 70

4.1.2 Circular Tripping Areas

To define a circle with the center at the origin of the coordinates, simply enter the radius. Additional

entries can be made to move the center of the circle along the positive resistance axis. Depending

on where the center is, the circle is known as:

● An Impedance Circle:

The center is located in the origin of the coordinate.

● A Modified Impedance Circle:

The center is located between origin of the coordinates and positive radius. The circle passes

through the reactance axis of the impedance area.

● A Conductance Circle:

The center of the circle is located right at the positive radius. Thus, the reactance axis is simply

a tangent of the circle.

This type of protection device is technically known as an analogous protection device. Protection

devices are complicated mechanical measurement devices.

4.1.3 Quadrilateral-Shaped Tripping Areas

The simplest form of the impedance quadrilateral is a rectangle. To define these, simply enter a

value for resistance and reactance in the first quadrants. PSS SINCAL then constructs an area

symmetrical to the resistance and reactance axes. Entering an angle changes the rectangle to a

diamond.

Unlike circles, the two different shapes have no special names:

● Rectangular impedance quadrilateral

● Diamond-shaped impedance quadrilateral

Technically, these protection devices are known as digital protection devices and resemble modern

PCs.

Since digital protection devices have become much cheaper to buy and maintain than analogous

protection devices, digital devices are replacing analogous ones. To protect the network when

devices are exchanged, the new devices must be assigned the same tripping area as the old

devices. Newer digital protection devices can also simulate circular tripping areas (digital

analogous protection).



April 2010 71

4.1.4 Common

How these devices work:

● Digital protection device with settings R, X, Z and angle phi

Measurement types supported:

● Impedance Circle

● Modified Impedance Circle

● Conductance Circle

● Impedance Quadrilateral

● Reactance Quadrilateral

● MHO Circle

● MHO Circle Polarized

Rated currents supported:

● PSS SINCAL does not check for a specific rated current.

Zone R [Ohm] X [Ohm] Z [Ohm] Angle phi [°]

1 0.001 to 9999.000 (step of 0.001)

0.001 to 9999.000 (step of 0.001)

0.001 to 9999.000 (step of 0.001)

30 to 90 (step of 1)

2 - " - - " - - " - Such as phi1

3 - " - - " - - " - - " -

IP - " - - " - - " - - " -

PP - " - - " - - " - - " -

Procedural Simulation

The primary value for R, X and Z is calculated from

curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX

or

curr

voltsecpri ü

üZZ



April 2010 72

4.1.5 7SA500, 7SA501 and 7SA502


● Digital protection devices with settings R and X




● 1 ampere

● 5 ampere

Zone R [Ohm] X [Ohm]

1 0.05 to 65.32 (step of 0.01) 0.05 to 65.32 (step of 0.01)

2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -

The setting range is true for devices with 1A rated current and for devices with 5A rated current.

The tripping area is a rectangular impedance quadrilateral.


PSS SINCAL determines an internal transformer factor using the rated current with

0,1

Iü n

int

The primary value for R and X is calculated from

intcurr

voltsecpri üü

üRR

or

intcurr

voltsecpri üü

üXX



April 2010 73

4.1.6 7SA510, 7SA511 and 7SA513






● 1 ampere

● 5 ampere



2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -





0,1

Iü n

int


intcurr

voltsecpri üü

üRR

or

intcurr

voltsecpri üü

üXX



April 2010 74

4.1.7 7SA522


● Digital protection device with settings R, X, Z and angle phi



● MHO Circle

● MHO Circle Polarized


● 1 ampere

● 5 ampere


1 0.005 to 250.000 (step of 0.001)

0.005 to 250.000 (step of 0.001)

0.005 to 200.000 (step of 0.001)

30 to 90 (step of 1)

2 - " - - " - - " - such as phi1

3 - " - - " - - " - - " -

IP - " - - " - - " - - " -

PP - " - - " - - " - - " -


The tripping area is a diamond-shaped impedance quadrilateral.



0,1

Iü n

int


intcurr

voltsecpri üü

üRR

or

intcurr

voltsecpri üü

üXX

or

intcurr

voltsecpri üü

üZZ



April 2010 75

4.1.8 7SA610, 7SA611, 7SA612, 7SA631 and 7SA632


● Digital protection devices with settings R, X and angle phi




● 1 ampere

● 5 ampere

1 ampere rated current

Zone R [Ohm] X [Ohm] Angle phi [°]

1 0.05 to 250.00 (step of 0.01) 0.05 to 250.00 (step of 0.01) 30 to 90 (step of 1)

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -


Zone R [Ohm] X [Ohm] Angle phi [°]

1 0.01 to 50.00 (step of 0.01) 0.01 to 50.00 (step of 0.01) 30 to 90 (step of 1)

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -




curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX



April 2010 76

4.1.9 7SL13


● Digital protection device with settings X and RX




● 1 ampere

● 5 ampere

Zone X [Ohm] R/X [1] Angle phi [°]

1 Resistance chain: 0.02, 0.04, 0.08, 0.15, 0.30, 0.50, 1.00, 2.00, 4.00, 8.00, 16.00 and 32.00

2,00 88

2 Resistance chain: 0.02, 0.04, 0.08, 0.15, 0.30, 0.50, 1.00, 2.00, 2.00, 5.00, 10.00, 10.00 and 10.00

- " - Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -


The tripping area is a diamond-shaped impedance quadrilateral with sides that are always inclined

by 2 degrees.


Note that resistors must have the X value on the secondary side.


0,1

Iü n

int

Resistance chains of the individual zones have a serial connection with a base resistance of

0.1 ohm. PSS SINCAL automatically adds the base resistance to the indicated settings. When

these settings are passed on in protection device configuration, you need to be very careful that the

values are not reduced a second time by the base resistance. The primary value for R and X is

calculated from

intcurr

voltsec1pri1 üü

ü

X/R

)0,2tan(0,1)X1,0(X

intcurr

voltsec2sec1pri2 üü

ü

X/R

)0,2tan(0,1)XX1,0(X



April 2010 77

intcurr

voltsec3sec2sec1pri3 üü

ü

X/R

)0,2tan(0,1)XXX1,0(X

or

X/RXRpri1pri1

X/RXRpri2pri2

X/RXRpri3pri3

4.1.10 7SL17, 7SL24, 7SL70 and 7SL73


● Digital protection devices with settings X and R




● 1 ampere

● 5 ampere

Zone X [Ohm] R/X [1] Angle phi [°]

1 Resistance chain: 0.02, 0.04, 0.08, 0.15, 0.30, 0.50, 1.00, 2.00, 4.00, 8.00, 16.00 and 32.00

1.00 to 4,00 (step of 1) 88

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -



by 2 degrees.




0,1

Iü n

int



April 2010 78


0.1 ohm. PSS SINCAL automatically adds the base resistance to the indicated settings. When

these settings are passed on in protection device configuration, you need to be very careful that the

values are not reduced a second time by the base resistance. The primary value for R and X is

calculated from

intcurr

voltsecpri üü

ü

X/R

)0,2tan(0,1)X1,0(X

or

X/RXRpripri

4.1.11 EPAC3100, EPAC3400, EPAC3500, EPAC3600 and EPAC3700






● 1 ampere

● 5 ampere




2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -






April 2010 79

curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX

4.1.12 LZ91 and LZ92


● Digital protection devices with settings M, N and R/X




● 1 ampere

● 5 ampere

Zone M [1] N [1] R/X [1] Angle phi [°]

1 0.1, 0.5 or 5.0 1.0 to 99.0 (step of 1.0) 1.0 to 5.0 (step of 1.0) 85

2 0.1, 1.0 or 10.0 - " - - " - Such as phi1

3 - " - - " - - " - - " -

IP - " - - " - - " - - " -

PP - " - - " - - " - - " -



by 5 degrees.




0,1

Iü n

int


intcurr

voltpri üüX/RN

ü))0,5tan(0,1(100MX

or



April 2010 80

X/RXRpripri

4.1.13 PD531 and PD551






● 1 ampere

● 5 ampere



1 0.10 to 10.00 (step of 0.01) and 10.0 to 200.0 (step of 0.1)

0.10 to 10.00 (step of 0.01) and 10.0 to 200.0 (step of 0.1)

2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -



1 0.02 to 10.00 (step of 0.002) and 10.0 to 40.0 (step of 0.02)

0.02 to 10.00 (step of 0.002) and 10.0 to 40.0 (step of 0.02)

2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX



April 2010 81

4.1.14 PD532 and PD552


● Digital protection devices with settings R, X, Z and angle phi





● 1 ampere

● 5 ampere



1 0.10 to 200.00 (step of 0.01)

0.10 to 200.00 (step of 0.01)

0.05 to 200.00 (step of 0.01)

40.0 to 90.00 (step of 1.0)

2 - " - - " - - " - Such as phi1

3 - " - - " - - " - - " -

IP - " - - " - - " - - " -

PP - " - - " - - " - - " -



1 0.02 to 40.00 (step of 0.01)

0.02 to 40.00 (step of 0.01)

0.01 to 40.00 (step of 0.01)

40.0 to 90.00 (step of 1.0)

2 - " - - " - - " - Such as phi1

3 - " - - " - - " - - " -

IP - " - - " - - " - - " -

PP - " - - " - - " - - " -

The tripping area is a diamond-shaped impedance quadrilateral (settings R, X and angle phi) or an

impedance circle (set at Z).



curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX

or



April 2010 82

curr

voltsecpri ü

üZZ

4.1.15 R1KZ4, R1KZ4A, RK4 and RK4A


● Analogous protection devices with the setting R and the measurement range c






● 1 ampere

● 5 ampere

Zone R [Ohm] c [1]

1 Resistance chain: 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2 0.1, 0.2, 0.5, 1.0, 2.0, 5.0 or 10.0

2 Resistance chain: 0.2, 0.4, 0.8, 1.6 and 3.2 Such as c1

3 Resistance chain: 0.4, 0.8, 1.6 and 3.2 - " -

IP Resistance chain: 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, 10.0, 20.0 and 962.7 - " -

PP - " - - " -


The tripping area is an impedance circle, a modified impedance circle or a conductance circle.



0,5

Iü n

int


1 ohm. PSS SINCAL automatically adds the base resistance to the indicated settings. When these

settings are passed on in protection device configuration, you need to be very careful that the

values are not reduced a second time by the base resistance. Set the diameter of the circle of the

respective measurement type. The primary value for R is calculated from

intcur

voltsecpri üü

ü)1R1(c1R

or



April 2010 83

intcurr

voltsecsecpri üü

ü)2R1R1(c2R

or

intcurr

voltsecsecsecpri üü

ü)3R2R1R1(c3R

4.1.16 R1KZ7 and R1KZ7G


● Analogous protection devices with the setting R, the measurement range c and the angle phi






● 1 ampere

● 5 ampere

Zone R [Ohm] c [1] Angle phi [°]

1 Resistance chain: 0.1, 0.2, 0.3, 0.3, 1.0, 2.0, 3.0 and 3.0

0.1, 0.2, 0.5, 1.0 or 2.0 0.0, 20.0, 30.0, 40.0, 50.0 or 55.0

2 Resistance chain: 0.2, 0.4, 0.4, 1.0, 2.0, 3.0 and 3.0

Such as c1 Such as phi1

3 - " - - " - - " -


The tripping area is an impedance circle, a modified impedance circle or a conductance circle.



0,5

Iü n

int








April 2010 84

intcurr

voltsecpri üü

ü)1R1(c1R

or

intcurr

voltsecsecpri üü

ü)2R1R1(c2R

or

intcurr


ü)3R2R1R1(c3R

4.1.17 R1Z25, R1Z25A and R1Z23B


● Analogous protection devices with the setting R, the measurement range c, the correction

factor C3 and the angle phi





● 1 ampere

● 5 ampere


1 Resistance chain: 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2

0.1, 0.2, 0.5, 1.0, 2.0, 5.0 or 10.0 60.0, 64.0, 68.0, 71.0, 74.0, 76.0, 78.0 or 80.0

2 Resistance chain: 0.4, 0.8, 1.6 and 3.2

Such as c1 Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -


The tripping area is either an impedance circle or a modified impedance circle.



3C

Iü n

int



April 2010 85






intcurr

voltsecpri üü

ü)1R1(c1R

or

intcurr

voltsecsecpri üü

ü)2R1R1(c2R

or

intcurr


ü)3R2R1R1(c3R

4.1.18 R1Z27


● Analogous protection device with the setting R, the measurement range c and the angle phi





● 1 ampere

● 5 ampere


1 1.0000 to 2.50000 (step of 0.0001) 0.5, 1.0, 2.0, 5.0, 20.0 or 50.0 60.0, 65.0, 70.0, 75.0 or 80.0

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -







April 2010 86

0,1

Iü n

int

For each zone, the resistance potentiometer must be assigned continuous values. The

measurement range can be entered individually for each zone. Set the diameter of the circle of the


intcurr

voltsecpri üü

üRcR

4.1.19 RD10


● Analogous protection device with the setting R and the measurement range c




● 1 ampere

● 5 ampere


Zone R [Ohm] c [1]

1 0.25000 to 6.25000 (step of 0.00001) 1.0, 4.0 or 8.0

2 - " - Such as c1

3 - " - - " -

IP - " - - " -

PP - " - - " -


Zone R [Ohm] c [1]

1 0.05000 to 1.25000 (step of 0.00001) 1.0, 4.0 or 8.0

2 - " - Such as c1

3 - " - - " -

IP - " - - " -

PP - " - - " -

The tripping area is an impedance circle.


For each zone, the resistance potentiometer must be assigned continuous values. The primary

value for R is calculated from



April 2010 87

curr

voltsecpri ü

üRcR

4.1.20 REL316


● Digital protection device with settings R and X




● 1 ampere

● 2 ampere

● 5 ampere

1 or 2 ampere rated current



2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX



April 2010 88

4.1.21 REL521 and REL561






● 1 ampere

● 5 ampere




2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




2 - " - - " -

3 - " - - " -

IP - " - - " -

PP - " - - " -




curr

voltsecpri ü

üRR

or

curr

voltsecpri ü

üXX



April 2010 89

4.1.22 SD124







● 1 ampere

● 5 ampere



1 1.00000 to 28.00000 (step of 0.00001) 0.25, 1.00 or 2.00 10.00 to 90.00 (step of 0.01)

2 - " - Such as c1 Such as phi1

3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -





3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -



For each zone, the resistance potentiometer must be assigned continuous values. Set the radius of

the circle of the respective measurement type. The primary value for R is calculated from

curr

voltsecpri ü

üRcR



April 2010 90

4.1.23 SD135


● Digital protection device with the setting R, the measurement range c and the angle phi




● 1 ampere

● 5 ampere



1 1.00000 to 10.00000 (step of 0.00001) 0.1, 1.0 and 6.0 72

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP 1.20, 1.35 or 1.50 Such as c1 - " -

PP - " - - " - - " -



1 1.00000 to 10.00000 (step of 0.00001) 0.02, 0.20 and 1.20 72

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP 1.20, 1.35 or 1.50 Such as c1 - " -

PP - " - - " - - " -





0,1

Iü n

int

PSS SINCAL calculates the primary value for R and X from the setting Z and the angle phi/2.

2sin

üü

üZcX

intcurr

voltsecpri

or



April 2010 91

)tan(X2

cosüü

üZcR

priintcurr

voltsecpri

4.1.24 SD135A


● Digital protection device with the setting R, the measurement range c and the angle phi




● 1 ampere

● 5 ampere

Zone Z [Ohm] c [1] Angle phi [°]

1 1.00000 to 10.00000 (step of 0.00001) 0.1, 1.0 and 10.0 72

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP 1.20, 1.35, 1.50, 2.00 or 3.00 Such as c1 - " -

PP - " - - " - - " -





0,1

Iü n

int


2sin

üü

üZcX

intcurr

voltsecpri

or

)tan(X2

cosüü

üZcR

priintcurr

voltsecpri



April 2010 92

4.1.25 SD14, SD14A and SD14B


● Analogous protection devices with the setting R and the measurement range c




● 1 ampere

● 5 ampere


Zone R [Ohm] c [1]

1 0.50000 to 12.50000 (step of 0.00001) 0.5, 1.0 or 4.0

2 - " - Such as c1

3 - " - - " -

IP - " - - " -

PP - " - - " -


Zone R [Ohm] c [1]

1 0.10000 to 2.50000 (step of 0.00001) 0.5, 1.0 or 4.0

2 - " - Such as c1

3 - " - - " -

IP - " - - " -

PP - " - - " -





curr

voltsecpri ü

üRcR



April 2010 93

4.1.26 SD34A






● 1 ampere

● 5 ampere





3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -





3 - " - - " - - " -

IP - " - - " - - " -

PP - " - - " - - " -





curr

voltsecpri ü

üRcR



April 2010 94

4.1.27 SD35


● Digital protection devices with the setting Z, the measurement range c and the angle phi




● 1 ampere

● 5 ampere


1 1.00000 to 10.00000 (step of 0.00001) 0.1, 1.0 and 6.0 90

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP 1.20, 1.35 or 1.50 Such as c1 - " -

PP - " - - " - - " -





0,1

Iü n

int


2sin

üü

üZcX

intcurr

voltsecpri

or

2cos

üü

üZcR

intcurr

voltsecpri



April 2010 95

4.1.28 SD35A and SD35C


● Digital protection devices with the setting Z, the measurement range c and the angle phi




● 1 ampere

● 5 ampere


1 1.00000 to 10.00000 (step of 0.00001) 0.1, 1.0 and 10.0 90

2 - " - - " - Such as phi1

3 - " - - " - - " -

IP 1.20, 1.35 or 1.50 Such as c1 - " -

PP - " - - " - - " -





0,1

Iü n

int


2sin

üü

üZcX

intcurr

voltsecpri

or

2cos

üü

üZcR

intcurr

voltsecpri



April 2010 96

4.1.29 SD36


● Analogous protection device with the setting R and the angle phi




● 1 ampere

● 5 ampere

Zone R [Ohm] Angle phi [°]


2 - " - Such as phi1

3 - " - - " -

IP - " - - " -

PP - " - - " -





0,1

Iü n

int



intcurr

voltsecpri üü

üRR



April 2010 97

4.2 Calculation Method

The task of this simulation procedure is to determine the settings for distance protection devices.

PSS SINCAL first uses the protection devices and protection device types in the network to

calculate minimum network impedance using a solution strategy.

Since there are different concepts or philosophies for determining primary network impedance

settings for protection devices, these are implemented as solution strategies in the simulation

procedure.

Currently PSS SINCAL can use the following solution strategies to determine network impedance:

● DISTAL Strategy:

This strategy is based on DISTAL. The distance protection devices are set according to

absolute selectivity.

● Line Impedance Strategy:

This strategy determines the impedance areas of protection devices and their settings from the

sum of the line impedances in the protection zones.

● Line Impedance Strategy Connected:

This strategy determines the settings for protection devices from line impedances in the

network.

● Medium-Voltage Network Strategy:

This strategy determines the impedance areas of protection devices and their settings from

loop impedances in the protection zones.

PSS SINCAL uses time sequence factors to calculate the primary bend impedance from the

primary network impedance. The primary bend impedance can also be entered directly by the user.

PSS SINCAL uses transformers, protection device types and the primary bend impedance in the

network to calculate the secondary values actually set at the protection devices. PSS SINCAL

always rounds off the settings to the next possible lower setting.

Protection route simulation is a way to determine whether the tripping behavior you want can

actually be achieved with the settings that have been calculated.

All strategies that determine tripping times are identical to calculating impedance. PSS SINCAL

uses preferred tripping times, tripping distance and the tripping times of the subordinate protection

devices to calculate tripping time.

4.2.1 Entries for Determining Impedance

Entries in Calculation Settings, Network Levels and protection device data define how

PSS SINCAL calculates primary network impedance data.

Defining with Protection Device Data

If the selective grading factor – zone 2 is greater than 100 percent, PSS SINCAL uses the

primary impedance from Zone 1.

If the selective grading factor – zone 3 is greater than 100 percent, PSS SINCAL uses the

maximum network impedance from Zone 2.



April 2010 98

If the directional final time of the protection device is smaller than or equal to the tripping time of a

particular zone, PSS SINCAL uses the primary impedance of the previous zone. This entry has

higher priority than the entry for selective tripping factors.

General Definitions

PSS SINCAL uses the smallest impedance up to the location of the next protection device as the

primary impedance from Zone 1. If the time difference between the tripping zone of the current

protection device and that of the following protection device is greater than the minimum selective

tripping, PSS SINCAL calculates the selective tripping factor for this zone. This means that this

zone has an effect that goes beyond the next protection device.

OC protection devices at a transformer limit the protection zone. PSS SINCAL does not, however,

use the impedance up to this network point to determine the smallest impedance from Zone 1.

PSS SINCAL uses the small impedance up to the bend of Zone 1 or Zone 2 from the next

protection device as the primary impedance for Zone 2 or Zone 3, if the bend is located in Zone 2

or Zone 3.

If the bend impedance of the second or third level is less than that of the preceding level,

PSS SINCAL uses the impedance of the preceding level to calculate the settings.

If the tripping time of a level is less than or equal to the tripping time for directional current

energizing, PSS SINCAL sets the level equal to the prior level.

Defining with Calculation Settings

Protection Settings – Calculation Settings determine the:

● Strategy used to calculate primary network impedance,

● Shortest distance of the second protection zone,

● Calculation sequence for the tripping levels,

● Additional information used to calculate primary network impedance

● Delay times

Treatment of Transformers

The attribute for Treatment of Transformers in the calculation settings for Protection Settings

influences the protection zone in calculations for primary network impedance. PSS SINCAL

provides the following options:

● Consider transformers

● Ignore radial transformers

● Ignore transformers



April 2010 99

In the network topology below the first protection device depends on the consideration of

transformers.

Illustration: Network topology depending on user input

With Consider transformers, all network elements remain in the protection zone.

Illustration: Protection zone when transformers are considered

Ignore radial transformers ignores all transformers at the end of a radial network if there is no

supply source.

Illustration: Protection zone without radial transformers

G

G

G



April 2010 100

Ignore transformers ignores all transformers.

Illustration: Protection zone without transformers

Treatment of Supply Nodes

The attribute for Treatment of Supply Nodes in the calculation settings for Protection Settings

influences the protection zone in calculations for primary network impedance. PSS SINCAL

provides the following options:

● None

● Slack node

● Slack node and transformer

● Slack and transformer opposite node

In the network topology below the first protection device depends on the treatment of supply nodes.

Illustration: Network topology with direct supply source depending on user input

Without special treatment all network elements remain in the protection zone. The protection

device in the parallel feed limits the protection zone. The protection device is graded according to

what has been entered for the individual zones.

Illustration: Protection zone without special treatment of supply nodes



April 2010 101

When a slack node limits the protection zone, the protection zone ends at this node. The

remaining network area is a radial network. The protection device is graded according to what has

been entered for radial lines.

Illustration: Protection zone with limit at slack nodes

Since the supply source is attached directly at the network, any further setting possibilities will

create the same protection zone as if limited by the slack node. There needs to be a feed by a

transformer to have additional possibilities.

Illustration: Transformer-fed network topology depending on user input

When slack node and transformer limit the protection zone, the protection zone ends at these

nodes or elements. The protection zone ends behind the transformer or at the protection device at

the parallel feeder. The protection device is graded according to what has been entered for

individual zones.

Illustration: Protection zone with limit at slack node and transformer

When the slack and transformer opposite node limits the protection zone, the protection zone

ends at these nodes or elements. The remaining network area is a radial network. The protection

device is graded according to what has been entered for radial lines.

Illustration: Protection zone with limit at slack node and transformer opposite node



April 2010 102

Delay Times

PSS SINCAL uses delay times as preferential tripping times, if the tripping time of the level is 0.0

seconds and the tripping distance is kept.

If the tripping distance is greater than the tripping time entered in the minimum delay times, the

tripping time of the second level is set to the desired tripping time.

Example: Determining times when minimum tripping time is undercut

If the tripping distance is smaller than the tripping time entered in the minimum delay times, the

time of the second level is set to the tripping time of the first level of the following protection device

plus the minimum tripping time. The tripping time of the second level must be more than the

desired tripping time.

Example: Determining times when the minimum tripping time is undercut

Defining with Network Level Data

The network level defines the arcing reserve for individual voltage levels and for individual

measurement types. Depending on what has been entered, PSS SINCAL calculates the arcing

reserve before it determines the settings for bend impedance.

Factor R from X

kkRkkSetjX)X(absfRZ

Z

t

t21 t11

t12 = t21 + ts

ts

tv1

tv2

Z1 Z2

Z

t

t21 t11

t12 = tv2

ts

tv1

tv2

Z1 Z2



April 2010 103

R Arc (primary)

kLBkkSetjXRRZ

Minimum R/X

for Rk/jXk < Minimum R/X:

kkkSetjXX/RXZ

for Rk/jXk ≥ Minimum R/X:

kkkSetjXRZ

ZkSet … Bend impedance to determine setting

Rk … Bend resistance according to strategy

Xk … Bend reactance according to strategy

RLB … Arcing resistance

R/X … Minimum value for R/X ratio

fR … Factor for resistance

4.2.2 Type of Measurement

This is the impedance area (R/X) that can be set at the protection device. Depending on the type of

distance protection device, PSS SINCAL supports different types of measurement – and thus

impedance areas.

Older protection devices work in the same way and have a circular tripping area. Newer protection

devices work digitally and can recreate both a circular-shaped tripping area and a quadrilateral-

shaped tripping area.

PSS SINCAL provides the following types of measurement and impedance areas.

● Analogous Impedance Measurement – Impedance Circle

● Analogous Measurement of Mixed Impedance – Modified Impedance Circle

● Analogous Conductance Measurement – Conductance Circle

● Digital Quadrilateral – Impedance Quadrilateral (with/without Entering R/X > 1)

● Digital Reactance Measurement – Reactance Quadrilateral

● Digital MHO – MHO Circle

● Digital MHO Polarized – MHO Circle Polarized

When it calculates settings for distance protection devices, PSS SINCAL constructs simplified

areas from bend impedance and then uses the available settings to construct an area as similar to

this as possible at the protection devices themselves.



April 2010 104

Summary of important formulas for calculating the settings:

Formula sign Description

R Resistance

X Reactance

22 XRZ Impedance

R

XRZ

G

1 2

k Conductance (reciprocal conductance calculated as resistance)

c Measurement range

Impedance Circle

Impedance circles have their center at the origin of the coordinate of the R/X level.

As the smallest primary network impedance, PSS SINCAL uses the one producing the smallest the

smallest absolute value.

22

volt

curr XRü

ü

c

2r

or

c

Z2r sec

Illustration: Impedance area

Modified Impedance Circle

Modified impedance circles have their diameter on the R axis in the R/X level and passing through

the x-axis at the bend reactance.

As the smallest primary network impedance, PSS SINCAL uses the one producing the smallest

absolute value.

X05,1ü

ü

c

2r

volt

curr

X

R



April 2010 105

or

c

X1,2r sec

Illustration: Modified impedance area

Conductance Circle

Conductance circles have their diameter on the R axis in the R/X level and touching the x-axis.


conductance circle.

PSS SINCAL determines the radius of the conductance circle as follows:

R

XR

ü

ü

c

1r

2

volt

curr

or

c

secZr k

Illustration: Conductance area

X

R

X

R



April 2010 106

Impedance Quadrilateral

This describes the impedance area with a quadrilateral. Entering the angle phi changes the shape

of the R/X area.

When PSS SINCAL determines the setting. it sees the impedance quadrilateral as a simplified

rectangle. If it can have an angle, PSS SINCAL uses the angle of the bend impedance of the first

level as the setting for distorting the quadrilateral.


reactance value.

Illustration: Impedance quadrilateral

Reactance Quadrilateral

The reactance quadrilateral is a rectangle in the R/X level that has a prescribed X Value. The R

direction has no limit. The largest value becomes the R value. PSS SINCAL automatically adjusts

the reactance quadrilateral during protection simulation.


reactance value.

Illustration: Reactance quadrilateral

X

R

X

R

Z



April 2010 107

MHO Circle

MHO circles pass through the origin of the coordinate and have their diameter on the straight line.

PSS SINCAL uses the angle of the bend impedance of the first level as the angle of the straight

line.


MHO circle with the straight line.

To calculate the MHO circle from impedance with R and X, a straight line, normally at the

impedance indicator, has to pass through the point R/X in the R/X level. The intersecting point

becomes the diameter of the MHO circle.

Illustration: MHO circle – forward

Illustration: MHO circle – backward

MHO Circle Polarized

The polarized MHO circle is a circle based on the MHO circle. The polarization increases or

decreases the circle in the direction opposite to the fault.

PSS SINCAL always uses the pre-fault voltage to calculate polarization voltage according to

following formula:

prepreactprepVkV)k0,1(V

Vp … Polarization voltage

X

R

Z

X

R

Z



April 2010 108

kpre … Setting for evaluation factor for pre-fault polarization

Vact … Current voltage of the impedance loop

Vpre … Pre-fault voltage of the impedance loop

The setting for the evaluation factor for pre-fault polarization is for all levels. PSS SINCAL

calculates any change in impedance from the polarization voltage and the current as follows:

act

ppre I

VZ

Vp … Polarization voltage

Iact … Present current of the impedance loop

Zpre … Change in impedance at pre-fault voltage polarization


unpolarized MHO circle with the straight line.

To calculate the unpolarized MHO circle from impedance with R and X, a straight line that is

normally to the impedance indicator has to pass through the point R/X in the R/X level. The

intersecting point becomes the diameter of the MHO circuit.

Illustration: MHO circle – forward – forward fault

Illustration: MHO circle – forward – backward fault

X

R

Z

Zv

X

R

Z

Zv



April 2010 109

4.2.3 Selective Grading Factors

Impedance characteristics are set in the protection device depending on circuit breaker locations

and their selective protection zones in the network. Tripping is initiated if the measured impedance

is within the set characteristic and after the corresponding delay time has elapsed.

Tripping diagrams with impedance-time characteristics provide a good method to visualize

protection device settings.

The selective grading factors determine the reach of the protection zones, based on a percentage

value of the line impedance.

Illustration: Selective grading factors

If the zone no longer has any subordinate protection device, PSS SINCAL replaces the grading

factor of the zone (st1, st2, and st3) with the grading factor for stub cables (stStich).

Zone 1

1L1

1RZ

100

stZ

Zone 2

100

st

100

stZZZ 21

2L1L2R

Zone 3

100

st

100

st

100

stZZZZ 321

3L2L1L3R

Auto-Reclosure

100

stZZ errint

1Lerrint

ZL1 ZL2 ZL3

ZR1

ZR2

ZR3

ZR1'

ZR2'



April 2010 110

Teleprotection

100

stZZ

comp1Lcomp

Recommended Selective Grading Factors

%90ststst321

%120ststcomperrint

Zones of the Next Protection Device

100

stZZ 1

2L'1R

100

st

100

stZZZ 21

3L2L'2R

4.2.4 DISTAL Strategy

The DISTAL strategy sets the protection devices according to absolute selectivity.

The following are true:

● PSS SINCAL observes all protection devices in the direction of the line.

● Except for the branch with the protection device, all branches leading away from protection

devices are disconnected.

● A generator is created at the protection device location to determine the network impedance of

the protection device.

● The real generators in the network can either be deactivated or considered in the calculations.

● A minimum value of R/X is entered for impedance quadrilaterals to assure there will be no

unfavorable impedance areas (too long and narrow).

Types of Protection Zones

Distance protection devices determine the fault impedance from the line voltage and current at the

location.

Protection devices can measure the fault removal correctly only if the line connecting the protection

device to the fault location is an unbranched radial line or if there is a tree with only one supply

source at the location.



April 2010 111

Illustration: Protection zone as a radial line

4321K

RZZZZ

I

VZ

Illustration: Protection zone as a tree

321K

RZZZ

I

VZ

Each parallel path increases the range of the protection device, and the protection device "sees"

the fault as being closer.

Illustration: Protection zone with parallel path

P2

P21

P2

P21R ZZ

ZZZ

ZZ

ZZZZ

Each intermediate supply source (between the protection device and fault location) shortens the

range of the protection device; i.e. the protection device "sees" the fault as being farther away.

Z1

ZP

Z2

Z1

Z3 Z2

JK

Z1

Z3 Z2

Z4

JK



April 2010 112

Illustration: Protection zone with intermediate supply source

22111Z)II(ZIV

21

211

1R

ZI

IIZ

I

VZ

Normally, a meshed network has several supply sources. The following diagram shows a path in a

meshed network where the range of the protection devices at the beginning of the route is to be

checked:

Illustration: Protection zone in a meshed network

1 2

3 4

~

J2 J1

V

~



April 2010 113

Networks can be converted to the form below:

Illustration: Converted meshed network

Normally meshed networks have:

● A supply source with pre-reactance at each station

● Parallel connections between all stations

All supply sources and parallel connections must be considered to find the exact setting of the

protection device.

This setting is correct only for this basic network condition.

Changing feed ratios or switching lines ON/OFF, however, does change the impedance measured

by the protection device. Particularly when intermediate supply sources are turned OFF, the

protection device measures "too far". This means there is no selective tripping, and the devices are

not turned OFF properly.

To assure selective tripping for all feeding and switching conditions, you need to select the network

condition where the protection device measures farthest. This means the protection device can

only measure distances that are shorter than this and never measures beyond the permissible

selective tripping limit.

Protection devices have maximum range:

● If you have eliminated all intermediate supply sources that might shorten the range (as

explained above)

● If there is a supply source at the protection device

● If you have considered all parallel paths (parallel paths starting from Station 1 are not

considered since they are an intermediate supply source and NOT a parallel path for the short

circuit current running through the protection device)

1 2 3 4

~ ~ ~ ~



April 2010 114

The following is a network diagram that has been converted to determine the settings of Protection

Device 1:

Illustration: Converted network diagram

ZP1, ZP2 and ZP3 are replacement impedances for the entire parallel subnetwork. (Parallel resistors

of the subordinate network level are not considered since relatively high-resistance dead-end

transformers block them).

These tripping resistors guarantee the highest degree of selectivity. Even in worst-case network

switching and feeding scenarios, tripping will be selective (worst case-selective tripping).

Zone 2 must go beyond the remote station to include busbar faults with arcs. This is particularly

important for busbars that are not protected.

Sequence for Calculating the Tripping Zones

Calculating Zone 1

Zone 1 can be calculated exactly. Since accurate calculations are unnecessary, a selective grading

factor of 90% is recommended.

Calculating Zone 2

In the next zone, PSS SINCAL first considers all the parallel resistors. Then it checks whether the

zone goes beyond the following station by a minimum percentage. This percentage can be set in

the Calculation Settings. If Zone 2 does go beyond the next station by this amount, PSS SINCAL

displays a warning message.

This assures a good compromise between selectivity and tripping. PSS SINCAL prints a log of the

actual range of Zone 2 as a percentage of the line with the protection device. This log should be

checked if PSS SINCAL displays a warning message.

Calculating Zone 3 (Normal with Grading Factor < 100 %)

The Zone 3 checks all the parallel resistors for selectivity. PSS SINCAL automatically shuts down

any line segments that Zone 3 does not reach. Selectivity is emphasized. Very rarely, however, a

protection device or switch can fail in the meshed network, and there can be somewhat longer

tripping times.

1 2 3 4

ZP1

ZP3

ZP2

~



April 2010 115

Calculating Zone 3 (Normal with Grading Factor ≥ 100 %)

The Zone 3 has to reach past the second station away to avert larger network shutdowns.

Illustration: Calculating Zone 3

3max213Rst)ZZ(Z

Here some additional lines can be turned OFF to prevent a larger network shutdown.

Calculating Zone 3 like Zone 2

The same impedance setting should be used for the Zone 2 and Zone 3.

4.2.5 Line Impedance Strategy

PSS SINCAL uses the line impedances in the network to calculate the settings of protection

devices.

The following is true:


● Parallel paths are observed separately.

● Ends of protection zones are observed separately.

● For the settings, PSS SINCAL uses the impedance sum that creates the smallest conductance

circle.


To determine the settings, PSS SINCAL simply adds up all the line impedances, similar to the way

many energy suppliers do in real networks.

Illustration: Protection zone as a spur

Z1

Z3 Z2

Z4

Z21 Z31

ZR3

Z22

Z23

Z32



April 2010 116

4321RZZZZZ

Illustration: Protection zone as a tree

4211RZZZZ

5212RZZZZ

6313RZZZZ

7314RZZZZ

Illustration: Protection zone with a parallel path

211RZZZ

312RZZZ

Determining the Conductance Circle

The conductance, or mho, circle is one whose diameter touches the r axis in the R/X level and the

x axis. To determine the conductance circle from impedance with R and X, a straight line that

normally goes to the impedance index through the point R/X in the R/X level has to intersect with

the r axis. The point of intersection is used for the diameter of the conductance circle.

Z1 Z2

Z3

Z1

Z6 Z3

Z4

Z5

Z7

Z2



April 2010 117

Illustration: Determining the diameter of a conductance circle

4.2.6 Line Impedance Strategy Connected

PSS SINCAL uses the line impedances connected in the network to calculate the settings of

protection devices.


● PSS SINCAL closes all switches

● PSS SINCAL observes all protection devices in the direction of the line

● Parallel paths are observed separately

● Ends of protection zones are observed separately

● For the settings, PSS SINCAL uses the impedance sum that creates the smallest conductance

circle.

The only difference between this strategy and Line Impedance Strategy is that the switches are

closed.

4.2.7 Medium-Voltage Network Strategy

Medium-Voltage Network Strategy uses minimal loop impedance at the protection device to

determine protection device settings.



● No modifications are made to the network.

● If there is a short circuit in the protection zone, there must be current and voltage at the

protection device.

● To determine minimum loop impedances for individual zones, PSS SINCAL calculates one

short circuit each directly behind every protection device limiting the protection zone.

● Entering a minimum value of R/X for impedance quadrilaterals assures ideal impedance areas

that are neither too narrow nor too high.


Distance protection devices investigate the fault impedance from line voltage and current found at

the location.

X

R d

ZRi

.



April 2010 118

For protection devices to measure the impedance up to the fault location correctly, the current from

the protection device has to create the remaining voltage at the protection device. If this does not

happen (i.e., because there are parallel paths), the loop impedance will increase.

Protection Zone – Zone 1 (without Parallel Paths to Create the Remaining Voltage)

The example below illustrates that the network acts as a radial network for the protection device.

This is true for all faults in the protection zone during the first time period.

Illustration: Fault at a common node

2211FIZIZV

11

11

1

F1Loop

ZI

IZ

I

UZ

22

22

2

F2Loop

ZI

IZ

I

UZ

Since both of these supply the same voltage, the protection device registers the correct impedance

up to the fault location.

Illustration: Fault in the middle of a parallel line

2122211FZI)ZZ(IV

2211

2211

1

F1Loop

ZZI

)ZZ(I

I

VZ

212

212

2

F2Loop

ZI

ZI

I

VZ

VF, IF

Z1 I1

IF

Z21 I2

Z3

Z22

IF

VF, IF

Z1 I1

Z2 I2

Z3



April 2010 119

Protection Zone – Zone 2 (with Parallel Paths to Create the Remaining Voltage)

In the example below, note that there is no increase in loop impedance before the second time

period.

Illustration: Fault at the end of the protection zone

3F223F11FZIZIZIZIV

31

F1

1

3F11

1

F1Loop

ZI

IZ

I

ZIZI

I

VZ

32

F2

2

3F22

2

F2Loop

ZI

IZ

I

ZIZI

I

VZ

21FIII

31

213

1

2111Loop

ZI

I1ZZ

I

IIZZ

32

123

2

2122Loop

ZI

I1ZZ

I

IIZZ

The loop impedance up to the fault location is no longer equal to the sum of the line impedances.

Since the fault current is divided between Lines 1 and 2, the registered loop impedance must be

greater than the sum of the line impedances.

VF, IF

Z1 I1

IF

Z2 I2

Z3



April 2010 120

4.3 Results of Settings Calculations

This simulation procedure generates results as settings calculated for distance protection devices

and diagrams (selective tripping schedules).

Calculated Settings

Illustration: Settings calculated for distance protection devices

PSS SINCAL lists the settings from the calculations in the data output form, If necessary, they can

also be used directly as input parameters in the settings. For a detailed description of how this is

done, see the example in Protection Device Settings.

Diagrams

For each protection device, PSS SINCAL generates two grading diagrams. These can be called up

with DI Device Settings – Grading Diagram (Z/t or X/t). The diagrams also have subordinate

protection devices in the protection zone. These diagrams show tripping behavior of the protection

devices over a period of time in dependence on the bend impedance calculated.

The bends in the diagram are the intersecting points (Z or X) of the impedance area with lines

through the origin of the coordinate and the bend that has been calculated. If directional current

energizing has been entered, PSS SINCAL will show this after the last available level.



April 2010 121

Since the bend impedance does not have to agree with the registered loop impedance, this tripping

behavior purely prognostic. Protection route simulation is used to determine whether the desired

tripping behavior can actually be achieved. If the registered loop impedance of the protection

device is not the same as the calculated bend impedance, this will produce different tripping

behavior in protection route simulation. In this case, protection device settings will need to be

calculated again using a different strategy, or modified by hand until the desired tripping behavior is

achieved.

Illustration: Diagram of DI Device Settings – Grading Diagram

Sometimes you also need to generate selective tripping diagrams for documentation without

determining the settings. Click Calculate – Protection Device Coordination – DI Device –

Charts in the menu to start this function.

4.4 Hints and Cautions

Note the following:

● The procedure does NOT let you automatically switch measurement types. If the distance

protection device cannot be set with this type, PSS SINCAL aborts the calculations and

displays an error message. This also happens if a distance protection device supports different

types of measurement and the required setting could be done with another type of

measurement.

● If Zone 2 is less than Zone 1 PSS SINCAL gives Zone 2 the same setting as Zone 1.

● If Zone 3 is less than Zone 2 PSS SINCAL gives Zone 3 the same setting as Zone 2.


Fault Detection

April 2010 122

5. Fault Detection

This procedure localizes a fault at a protection device, determining the precise position of the fault

in the supply network.

Modern protection devices save the impedance that caused the tripping when there is a fault.

These values let you calculate the position of the fault in the network.

Calculation Method

If there is a fault at a protection device (see the section on Protection Location in the chapter on

Data Description in the Input Data Manual), enter the impedances registered by the protection

device.

PSS SINCAL then goes through the network in the direction of the line looking for every protection

device that has these data. This search stops at the next or second to the next protection device in

the same direction.

Illustration: Principle of fault detection

PSS SINCAL calculates short circuits along these lines, which have been divided up depending on

detection accuracy. If the impedance measured is between the registered impedance of the

following two short circuit calculations, PSS SINCAL records the impedance as a hit. It also records

the distance from the starting node.

In the above example, the fault is in Line L2. The impedance (ZR) for the fault was registered at the

protection device. The simulation procedure indicates two possible locations of the fault – in Lines

L2 and L3 – for the impedance registered.

Fault detection accuracy can be set in the Calculation Settings. Note that higher detection accuracy

increases calculation time.

L1

L3

L2

ZR


Fault Detection

April 2010 123

Results of Fault Detection

PSS SINCAL displays all the results in the message box, so you can identify the network elements

that have faults (see the chapter on Messages in the System Manual).

Message in the example:

● Fault detection by one protection device(s) between 350.0 and 400.0 meters from the starting

node. (Line: L16, Protection Device: Dist in S9)

This message tells you how many protection devices registered the fault. It also lists the line where

the fault is presumably located, the distance from the fault to the starting node and the protection

devices that have registered the fault.


Dimensioning

April 2010 124

6. Dimensioning

PSS SINCAL calculates the minimum one-phase short circuit currents in low-voltage networks

according to VDE 0102 Part 2/11.75 and determines the maximum permissible amount of rated

fuse current for fuses.

A differentiation must be made between a normal circuit-breaking examination and a circuit-

breaking examination that is made after the load flow has been calculated. In the latter case, load

currents from the load flow calculations produces the minimum rated fuse currents and examining

the cut-off conditions produces the maximum rated fuse current. If the load current from the load

flow calculations is greater than the permissible rated fuse current after the circuit-breaking

condition, PSS SINCAL records this in the output log.

Only fuses in network areas with a rated voltage less than 1 kV are accepted. PSS SINCAL does

not check branches with short circuit currents less than 6 A. PSS SINCAL only accepts fuse areas

with a maximum of 3 limited fuses.

Dimensioning Calculation Procedures


Unload and check all network data

Create subnetwork using transformers

Check tripping condition

Have all fuse areas been calculated?

Yes

No

Determine fuse areas

Determine minimum short circuit power

Have all subnetworks been calculated?

Prepare results

Yes

No


Dimensioning

April 2010 125

6.1 Calculation Methods

Creating Subnetworks

Typically, networks are medium- and low-voltage networks. These low-voltage networks are

normally made up of several subnetworks.

Illustration: Network with various subnetworks

Since medium-voltage networks are recreated by the ensuing short circuit power at the transformer

on the high-voltage side, they can be eliminated from the calculations. The pending short circuit

power is entered in the field Short Circuit Alternating Power of Calculation Settings.

Subnetworks can be found with the help of the network analysis in the low-voltage network. Since

the neutral-point coupling between the subnetworks is ignored, each subnetwork can be calculated

and observed separately.

The maximum permissible rated fuse current must be determined separately for each fuse in the

low-voltage network. The minimum one-phase short circuit current for each fuse area must also be

determined. A fuse area is defined as the network up to the next fuse. A fuse area is also always

limited by a fuse or stub end.

PSS SINCAL searches for the location with the minimum total one-phase short circuit current I"kmin

in each fuse area. This is the basis for Determining the Rated Fuse Current.

Low-voltage network

Subnetwork1

Subnetwork2

Subnetworkn

Medium-voltage network


Dimensioning

April 2010 126

Radiating Networks

In a radiating network, the nearest fuse or the end of the line recreates the least favorable fault

location.

Illustration: Radiating network

Meshed Networks

Meshed networks are recreated here for several time periods called time steps. In the first time

step, all the fuses are still in the network and modifications to network topology have not yet been

calculated. PSS SINCAL takes fuse melting is taken into consideration in the subsequent time

steps.

Since PSS SINCAL can calculate maximum fuse areas with three limiting fuses, there is a

maximum of only three time steps:

Illustration: First time period

PSS SINCAL determines the location with the smallest one-phase total short circuit current Ik1 and

calculates.

)III(kI3N2N1N1k

IN2

Ik1

IN1

IN3

Trafo


Dimensioning

April 2010 127

Illustration: Second time period

In the second time step, PSS SINCAL recalculates the location with the smallest current Ik again

and recalculates Ik.

)II(kI3N1N21k

)II(kI2N1N22k

)II(kI3N2N23k

Ik21

IN3

IN1

Ik22

IN2 IN1

Ik23

IN2

IN3


Dimensioning

April 2010 128

Illustration: Third time period

In this third time step, only the stub ends and the installation locations of the fuses remain to be

checked.

1N31kIkI

2N32kIkI

3N33kIkI

Location of Minimum Total Short Circuit Current

The location that produces the minimum total short circuit current is easily found for radiating

networks and for the last time step for meshed networks. It is at the end of the fuse area (the stub

end or the beginning of the new fuse area).

Ik33

IN3

Ik31

IN1

Ik32

IN2


Dimensioning

April 2010 129

In meshed networks, short circuits are simulated at the nodes along the lines of the fuse area,

except for the last time step. The lines are divided into several imaginary sublines. Enter the

number of short circuit locations or lines in the field Subdivisions in the Calculation Settings.

Minimum Total Short Circuit Current

The minimum initial short circuit alternating current I"k1p can be determined in the following manner

according to VDE 0102 Part 2:

01

NTp1k zz2

V95.03"I

p1k"I … Minimum one-phase total short circuit current

NTV … Rated voltage of the low-voltage side of the transformer

… Positive-phase-sequence impedance

… Zero-phase-sequence impedance

0.95 * VNT is the driving voltage for calculating minimum one-phase total short circuit current.

Enter this value in the Calculation Settings.

Determining Rated Fuse Current

PSS SINCAL determines the rated fuse current from the minimum one-phase total short circuit

current and the number of picked-up protection devices using the following criteria:

● Safety factor (factor rated current)

● Conductor cross-section

● Thermal damage – short circuit

● Thermal load time – current and large control current

● Maximum breaking time

If one of the above criteria are violated, PSS SINCAL uses the next smaller of the rated currents

possible for this type data.

Safety Factor (Factor Rated Current)

Each fuse’s safety factor (factor rated current) is found in the input data for this fuse.

1z

0z


Dimensioning

April 2010 130

The following condition has to be met:

pickupNS

p1k

nI

"Ik

I"k1p … Minimum one-phase total short circuit current

k … Safety factor (rated current factor)

INS … Rated current fuse

nAnreg … Number of picked-up protection devices

Conductor Cross-Section

Depending on the conductor cross-section, the rated fuse current strengths below cannot be

exceeded at copper cables according to VDE 0636.

Rated current INArea [A] Conductor cross-section [mm2]

6 1

12 1,5

20 2,5

25 4

32 6

50 10

63 16

80 25

100 35

125 50

160 70

200 95

250 120

315 185

400 240

500 300

630 400

800 500

1000 600

1250 800

PSS SINCAL calculates all lines of a protection zone for minimum short circuit current and the

smallest cross-section for all the lines.


Dimensioning

April 2010 131


NAreaNSII

Thermal Damage – Short Circuit

PSS SINCAL uses the characteristic curves of the type data and the minimum short circuit current

to interpolate the tripping time for each rated fuse current. Current and time are used to determine

the thermal energy I2t. If the maximum thermal energy is less than that of the network elements to

be protected, PSS SINCAL selects the next smaller rated fuse current.


element2

fuse2 tItI

Thermal Load Time – Current and Large Control Current

The tripping current of the protection device that is supposed to trip can, by international definition,

be only 1.45 times the current maximum load of the lines. The large control current of the

protection device has to be used as the tripping current. The current maximum load is the thermal

limit current Ith found in the line data. The table below shows the large control current from the rated

current according to VDE 0636:

Rated current INS [A] Factor for large control current fI2 [p.u.]

Up to 4 2.1

5 to 10 1.9

11 to 25 1.75

Above 25 1.6

PSS SINCAL calculates all lines of a protection zone for minimum short circuit current and the

smallest thermal limit current of all the lines.


2NSthflII45,1

Maximum Breaking Time According to VDE 0100

Installation networks must have a maximum breaking time of five seconds according to VDE 0100.

PSS SINCAL uses type data characteristics and minimum short circuit current to interpolate the

tripping time for each rated fuse current. If the time is more than five seconds, PSS SINCAL selects

the next smaller rated fuse current.


5ttripping


Examples

April 2010 132

7. Examples

This chapter contains examples for Protection Coordination and Creating Protection

Documentation.

7.1 Example for Protection Coordination

Below is a simple example of how Protection Coordination works. The following descriptions

show:

● Presetting Calculation Settings

● Creating Protection Devices

● Making Fault Observations

● Making Fault Events

● Determining Settings for DI Protection Devices

● Checking Tripping Behavior for Protection Devices

● Starting the Protection Calculations

● Displaying and Evaluating the Results

● Generating Protection-Route Diagrams

Basic Data

All descriptions are based on the following network.

Illustration: Protection network with input data

When you install PSS SINCAL, the program automatically provides a network ("Example Prot"),

which can be used to check the simulation procedure.

The names of protection devices in the network are chosen so that devices at the beginning and

end of a protection route all have the same name and the device at the end has a "G". In the above

example, devices "D1" and "D1G" are in the protection route between "K1" and "K3".


Examples

April 2010 133

To calculate protection coordination, Protection Device Coordination in the Calculate –

Methods... menu has to be activated (see Presetting Calculation Methods in the chapter on User

Interface in the User Manual).

7.1.1 Presetting Calculation Settings

In the Calculation Settings screen form, click the Protection Settings tab to set parameters for

the calculations. To open the screen form, click the menu item Calculate – Settings...

Illustration: Data screen form for Calculation Settings – Protection Settings

Important are the settings in the first part of this tab. The Strategy field sets which procedure

PSS SINCAL uses. Enter the selective grading factor you want in Sel. Grading Factor – 2nd

Zone. If the distance is less than this value, PSS SINCAL will send a warning message.

For a detailed description of all available calculation settings, see the section on Protection Settings

– Calculation Settings in the chapter on Calculation Settings in the Input Data Manual.

7.1.2 Creating Protection Devices

The following examples show only how to create and edit protection devices. The instructions

describe how real networks are created (see the chapter on Using an Example to Work on a

Network in the System Manual).

The simplest way to create protection devices is to use the pop-up menu. To open it, right-click the

terminal of that network element where you want to add the protection device.


Examples

April 2010 134

Illustration: Creating protection devices with the pop-up menu

Select in the pop-up menu the desired protection device type in the Insert Protection Device

menu.

PSS SINCAL displays a data input form where you enter the name of the new protection device.

Illustration: Entering the name of the protection device

For distance-protection devices, the type needs to be entered. PSS SINCAL differentiates between

"predefined" and "user defined" distance-protection devices.

A special model simulates the settings and the impedance areas of "predefined" devices.

Impedance areas describe "user defined" devices.

Click OK, and PSS SINCAL opens the screen form for protection devices.


Examples

April 2010 135

Illustration: Location of the protection device

The left side of the dialog box has a browser with the new distance protection device. When the

new device is selected, PSS SINCAL displays the general data at the right side of the dialog box.

General data show, among other things, where the protection device, its pre-switched current and

voltage transformer and the directional element are located. See Protection Location for a detailed

description of all the fields.

General data can also be used to turn protection devices OFF (without deleting them). This

switches Out of service ON. PSS SINCAL disregards this protection device in the calculations. A

special protection device symbol shows that this has been switched OFF.

The settings of the protection devices are both device- and type-specific. Click Settings in the

browser to display and edit them.


Examples

April 2010 136

Illustration: Settings for impedance protection device

This screen form is used to define individual settings for the new impedance-protection device.

With predefined distance protection devices, select the type of protection device and the type of

measurement. Also enter the selective distance factors and the tripping times.

With user-defined distance protection devices, define the impedance area.

With OC protection devices, select the protection device type from the protection device database

and enter the settings in the dialog box.

7.1.3 Making Fault Observations

Fault Observation is used to place "faults" at nodes and terminals of network elements in the

network.

Fault observation is used by the following simulation procedures:

● Protection simulation

● Multiple faults

● Stability

The simplest way to create fault observations is to use the pop-up menu. To open it, right-click the

terminal of that network element where you want to add the fault observation.


Examples

April 2010 137

Illustration: Creating fault observations with the pop-up menu

PSS SINCAL displays a screen form for the fault observation.

Illustration: Data screen form for Fault Observation

For a detailed description of how to enter data for fault observations, see the section on the Fault

Observation in the chapter on General Control and Input Data in the Input Data Manual.

7.1.4 Making Fault Events

Fault events let you group different fault observations. The protection coordination treat fault

observations grouped in this way as simultaneous faults.

Select Insert – Additional Data – Fault Event… in the menu to define fault events.


Examples

April 2010 138

Illustration: Data screen form for Fault Event

Fault events only have a Fault Event Name and an Operating State. The status specifies whether

or not PSS SINCAL considers the package in the calculations.

You can assign individual fault observations to the fault events directly in the basic data of the fault

observation. Simply select the package you want in the Fault Event field.

7.1.5 Determining Settings for DI Protection Devices

In the procedure to determine protection device settings, PSS SINCAL uses set grading factors

and delay times to calculate settings for distance protection devices in individual protection areas.

Note that PSS SINCAL only calculates time settings for distance levels when 0.0 seconds has

been entered as the tripping time for the level.

Start to Determine Settings

To start DI device settings determination, click Calculate – Protection Device Coordination – DI

Device – Settings.

If the calculations can be done without errors, PSS SINCAL displays the following dialog box.


Examples

April 2010 139

Illustration: Calculated Distance Protection Device Settings dialog box

This dialog box lists all the distance protection devices in the network. PSS SINCAL automatically

selects all devices that have no settings (such as Device D5 here). You can also select additional

devices from the list.

Click Details… to open a data screen form listing all the attributes of the element selected. You

can also double-click an element in the list to open this data screen form.

To simplify the selection of protection devices, PSS SINCAL provides the following control buttons:

● Select All:

Selects all the displayed protection devices in the list.

● All Calculated:

Selects protection devices that have the status Calculated.

● Deselect All:

Resets the selection at all protection devices.

When the dialog box opens, protection devices are selected that have the status No data.

Click Select to highlight the protection device in the network diagram selected in the list.

Click Apply to close the dialog box. PSS SINCAL adds the calculated settings to the protection

devices you have selected. PSS SINCAL then uses these results as input data (settings) for the

protection device(s).

This dialog box can be opened again later. You even can open this pop-up menu in a free area of

the Graphics Editor and click Results – DI-Protection Device – Settings....

Results of Settings Calculations

PSS SINCAL calculates the settings for the protection device and then displays the following

screen form:


Examples

April 2010 140

Illustration: Screen form for distance protection devices

The settings for protection device D5 were used, and the status in the Type of Input Data field is

Calculated.

The status of the Type of Input Data field can be:

● No data:

This protection device still has no settings and no impedance areas for PSS SINCAL to use in

the protection simulation.

● Calculated:

PSS SINCAL has calculated the settings for this protection device. They can be overwritten.

● Manual:

The settings were entered by hand. This procedure will not modify the values.

PSS SINCAL calculates the settings and displays these in Calculated for Device D5 in the

browser. Click Calculated Settings to see the calculation results. These settings are always

available, whether or not the settings are used for the particular protection device.

In addition to settings, these calculation methods also generate diagrams as selective tripping

schedules. PSS SINCAL provides these in Diagram View under Protection Device Coordination

– DI Device Settings.


Examples

April 2010 141

Illustration: DI device settings – grading diagram

For a description of the calculation method, see the chapter on Calculation Procedure.

7.1.6 Checking Tripping Behavior for Protection Devices

PSS SINCAL simulates the starting and tripping behavior of all protection devices in the network.

PSS SINCAL considers both distance protection and overcurrent protection devices. For a detailed

description of this procedure, see the chapter on Protection Simulation.

Prerequisites

When checking tripping behavior, faults have to be observed in the network. Fault observations

symbolize faults in the network, for which PSS SINCAL checks the protection setting accuracy.

These can be connected to any network element (see the section on Making fault observations).

7.1.7 Starting the Protection Simulation

There are two types of calculations:

● Calculating all fault observations in the network

● Calculating a fault observation using the pop-up menu

To calculate all fault observations in the network, select the following menu items:

● Calculate – Protection Device Coordination – 3-Phase Short Circuit

● Calculate – Protection Device Coordination – 2-Phase Short Circuit

● Calculate – Protection Device Coordination – 2-Phase to Ground

● Calculate – Protection Device Coordination – 1-Phase to Ground

● Calculate – Protection Device Coordination – Fault Event

To observe a fault, open the pop-up menu for this fault observation and select the desired type of

calculations in the menu item Calculation at Fault.


Examples

April 2010 142

Illustration: Starting protection simulation with the pop-up menu

PSS SINCAL has a special Fault Event function that lets you simulate different faults in the

network simultaneously analogous to the multiple fault calculations. Manually defined Fault Events

combine different fault observations and create a package.

7.1.8 Displaying and Evaluating the Results

PSS SINCAL calculates the settings for the protection device and then displays the following

results in the Graphics Editor.

Illustration: Protection network with results

This example shows the results of the first loop for the fault observation in Line L8.

Protection Device D5, at the beginning of the line, and Protection Device D5G, at the end of the

line, have a "+". A plus means that the settings that have been entered could trip the devices.

PSS SINCAL also displays both devices in red. This shows that both devices may also have

tripped.

PSS SINCAL uses the following colors to designate tripping and pickup:

● Red – The protection device has tripped.

● Yellow – The protection device has been picked-up within the selective tripping time.

● Green – The protection device is picked-up.


Examples

April 2010 143

PSS SINCAL searches for protection devices that can trip in each fault examination. These

comprise all protection devices that limit the fault going forward.

In the network diagram, PSS SINCAL marks with a "+" all protection devices that can trip. This is

independent of the current status of the protection device (not picked-up, picked-up, etc.).

In the network diagram, PSS SINCAL marks with an "x" all protection devices that are not

supposed to trip but do so.

Selection of the Results with Toolbar

PSS SINCAL has a special toolbar to simplify selecting results. In protection simulation, select the

desired fault observation and flow in this toolbar. PSS SINCAL displays these results in the network

graphics and in the protection devices dialog box.

Activate this toolbar by clicking View – Toolbars – Results.

Illustration: Results toolbar

Information in the Message Box

In addition to the results displayed in the Graphics Editor, information can be obtained from

Messages.

Illustration: Protection results in the message box

The button HTML Log displays, as an HTML log, which protection devices in the current fault

observation and loop:

● May trip

● Have tripped

● Are picked-up or not picked-up


Examples

April 2010 144

Results in Diagrams

In addition to the results displayed in the Graphics Editor and the information box, PSS SINCAL

generates results in diagram form. To view this information, click View – Diagram View….

Illustration: Protection results in the diagram form

The diagrams for tripping area and tripping characteristics can be combined in the browser. Select

the protection devices you want to display in the diagram. For a detailed description, see the

section on Overlay Tripping Characteristics in the chapter on Diagram View in the System Manual.

7.1.9 Generating Protection-Route Diagrams

The network and its built-in protection devices are used to generate a wide variety of diagrams,

which can be used to check the correctness of the protection setting.

To generate protection-route diagrams, click Calculate – Protection Device Coordination –

Routes. PSS SINCAL can create diagrams for 3- and 2-phase short circuits and 2- and 1-phase to

ground.

To view this information, click View – Diagram View….

The simulation procedure generates the following protection-route diagrams:

● Tripping Behavior

● Ratio Impedances (Z)

● Ratio Reactances (X)

● Impedance and Tripping Areas

Note: In the diagrams for protection devices, PSS SINCAL can generate these diagrams only when

the output in the selective grading diagram is turned ON (see the section on Protection Location in

the chapter on Data Description in the Input Data Manual).


Examples

April 2010 145

The calculation settings control how protection-route diagrams are displayed on the screen. You

can define, for example, the displayed protection route, using the field zones for selective

grading diagrams. For a detailed description, see the section on Protection Settings – Calculation

Settings in the chapter on Calculation Settings in the Input Data Manual.

The following diagram shows the tripping behavior of Protection Device D5.

Illustration: Tripping behavior diagram

This diagram shows the impedance of the protection route, as well as the node and additional built-

in protection devices in the x axis. The y axis contains the tripping time of the particular zone.

Protection devices that face "forward" are displayed in the diagram with negative time (i.e. below

the x axis). In the example above, these are devices D5G and D8G.

7.2 Example for Creating Protection Documentation

Below is a simple example of how Creating Protections Documentation works. The following

descriptions show:

● Selecting Grading

● Creating the Protection Documentation

● Inserting a Diagram

Basic Data

This description is based on a medium size industrial network with both OC and DI protection

devices. Generally speaking, however, protection documentation can be for any network.


Examples

April 2010 146

Illustration: Protection network with overcurrent protection devices

PSS SINCAL allows protection documentation for all types of elements. But if you need additional

information such as, for example, input data and limits, the network has to have overcurrent

protection devices. This is why we have included them in this example.

7.2.1 Selecting Grading

For protection documentation you first need to select a grading in an individual view. This can be

done in a number of ways, such as, for example, manually, by selecting the route, etc.

Illustration: Grading selected in the network


Examples

April 2010 147

7.2.2 Creating the Protection Documentation

After you have selected the grading, it is possible to create protection documentation. Click Tools –

Create Protection Documentation… in the Basic View to activate the function.

Illustration: Dialog box for Create Protection Documentation

Use the Name input field to define the name (in this case "Doc 1") for the new view.

This dialog box has all appropriate views for the documentation, i.e. PSS SINCAL lists all empty

and open views. In this example we chose the new created view.

When Create legends for protection devices is switched ON, PSS SINCAL displays

supplementary information (for range and input data) for OC protection devices of the selected

grading. You can set the layout and the distances between legends and protection devices or

modify it later in the Protection Device Legend dialog box.

The Page settings section lets the user select the desired paper format and the basic unit for the

new view.

Press OK to close the dialog box, and PSS SINCAL creates the protection documentation in the

new view.


Examples

April 2010 148

Illustration: Protection documentation without diagrams

7.2.3 Inserting a Diagram

Once the protection documentation is finished, you can add a diagram. Simply click Insert –

Objects – Diagrams in the menu.

Click on the position where you want to insert the diagram with the mouse to open a dialog box

where you can select a diagram.

Illustration: Dialog box for Diagrams

In this example the Station 2 diagram was selected and the dialog box was closed with OK.


Examples

April 2010 149

Illustration: Protection documentation with a diagram

Protection

Documents

double logarithmic

rated currents

double linear

pss sincal

pss sincal

pss sincal

pss sincal

pss sincal