Edsa Paladin

SYNCHRONOUS MACHINE PARAMETERS ESTIMATION

EDSA MICRO CORPORATION 16870 West Bernardo Drive, Suite 330

San Diego, CA 92127 U.S.A.

© Copyright 2008

All Rights Reserved

Version 2.95.00 October 2008

Table of Contents

Program Overview ........................................................................................................................................ 1

Calculation Theory ........................................................................................................................................ 1

Overview................................................................................................................................................... 1

Calculations .............................................................................................................................................. 2

Longhand Calculation For Program Verification and Validation / QA/QC .................................................... 6

Getting Started .............................................................................................................................................. 8

Opening or Creating a File........................................................................................................................ 8

Opening Calculation Views..................................................................................................................... 10

Calcs|AC Resistance .............................................................................................................................. 11

Calcs|D-Axis X/SCR ............................................................................................................................... 12

Calcs|D-Axis Saturated X ....................................................................................................................... 13

Open Circuit Characteristic - Data Point Dialog ..................................................................................... 14

Calcs|Q-Axis X (1) .................................................................................................................................. 14

Calcs|Q-Axis X (2) .................................................................................................................................. 16

Getting Results ....................................................................................................................................... 16

Closing Views ......................................................................................................................................... 17

Saving the File ........................................................................................................................................ 18

The Toolbar............................................................................................................................................. 19

Command Reference .................................................................................................................................. 20

File Commands....................................................................................................................................... 20

Edit Commands ...................................................................................................................................... 21

Record Commands................................................................................................................................. 22

Record|Delete ............................................................................................................................................. 22

Clipboard Commands ............................................................................................................................. 23

Window Commands................................................................................................................................ 23

Help Commands ..................................................................................................................................... 24

References.................................................................................................................................................. 28

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Synchronous Paramaters

Program Overview EDSA Synchronous Machine Parameter Calculation program provides a series of “intelligent calculators” for determining equivalent circuit parameters and short circuit ratio for synchronous machines (motors and generators). These intelligent calculations are useful for various analyses and system simulation studies. The calculation is based on data that are readily available from the manufacturer, or can be obtained from field tests. Calculated parameters are: 1. Equivalent effective AC resistance 2. Direct-axis reactance (unsaturated Synchronous reactance) 3. Short Circuit Ratio (SCR) 4. Direct-axis reactance (saturated Synchronous reactance) 5. Potier reactance 6. Quadrature-axis reactance Synchronous Machine calculation files are stored in two parts. The master file is always named with an extension of *.SMP. The detail file is always named with an extension of *.SMD. A *.SMP file can contain information for multiple machines. All of the input data, as well as calculated results, for a machine are organized in a record. Calculation Theory Overview The synchronous machine characteristic curves are shown below.

In the steady-state analysis of a balanced three-phase power system, a synchronous machine is represented by a per-phase (phase to neutral) model. The parameters of the per-phase model of a synchronous machine are: 1. Effective AC resistance per phase 2. Direct-axis synchronous reactance per phase

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3. Quadrature-axis synchronous reactance per phase It may be noted that the direct- and quadrature-axis synchronous reactances of a round-rotor (non-salient pole) machine have same values. In determining the saturated synchronous reactance, the following assumptions are made: (a) Armature leakage reactance is constant and independent of saturation, (b) The load saturation curve (Field current versus resultant air-gap voltage) is exactly the same with the Open

Circuit Characteristic. According to assumption (b), the armature leakage reactance is equal to the Potier reactance. The program uses piece-wise linear approximation of the Open Circuit Characteristic to compute the Potier reactance. The Potier reactance value is used for armature leakage reactance. Since the load saturation curve and the Open Circuit Characteristic usually become vertically nearer together as saturation is increased to high values, the value of the armature leakage reactance can usually be measured with fair accuracy by measuring the Potier triangle at very high values of saturation. In such case, zero power factor test is to be carried out for high voltage and rated current. Usually, zero power factor test is carried out for rated voltage and rated current to determine the Potier reactance. In any case, armature leakage reactance is taken to be equal to the Potier reactance for any degree of saturation. Since saturation factor is dependent on the resultant air-gap voltage, saturated synchronous reactance is a function of resultant air-gap voltage. The program computes the saturation factor and saturated synchronous reactance for a set of voltages on Open Circuit Characteristic. Note that open circuit voltages are also resultant of the air-gap voltages.

Calculations Following are the tests required to compute effective ac resistance, direct-axis synchronous reactance (unsaturated and saturated), and short circuit ratio: 1. Open Circuit Characteristic 2. Short Circuit test:

(a) Field current required to give rated short circuit current (b) Three-phase short circuit load loss at rated current (c) Average temperature of the armature winding during short circuit load loss test

3. Zero-power factor test: Field current to give rated current and rated or higher terminal voltage at zero power factor

4. DC resistance test:

(a) Armature winding resistance per Y-phase; and (b) Average winding temperature during the test.

In order to compute the quadrature-axis synchronous reactance for a salient-pole machine, the following tests are used:

1. Slip test 2. Maximum lagging current test

In the following discussion, air-gap line (a-g line) refers to a line obtained from the Open Circuit Characteristic by extending the straight-line lower portion thereof. In the case lower portion is not linear, the air-gap line refers to a

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line drawn as a straight line of maximum possible slope that passes through the origin and is tangent to the Open Circuit Characteristic. The following are the common input variables:

VLB = Rated line voltage of the machine in kV STB = Rated three-phase MVA of the machine

Note: Machine voltage and MVA ratings are the bases for per unit quantities.

The following are the output variables: R = Effective AC resistance in per unit (p.u.) at sT = Unsaturated direct-axis synchronous reactance in p.u. duX SCR = Short circuit ratio = Potier reactance in p.u. pX

i,dsiLA X,SF,V = Resultant air-gap line voltage (also, the open circuit line voltage) in p.u. and and are respectively the corresponding saturation factor and saturated direct-axis

synchronous reactance in p.u.

iSF

i,dsX

qX = Quadrature-axis synchronous reactance in p.u. Calculation of Effective AC resistance (R) Below are the formulae used for calculating the effective ac resistance of armature.

dcR = DC resistance of armature per Y-phase in ohms T = Average temperature of armature winding in degree Celsius during DC resistance

measurement sT = Temperature in degree Celsius, at which effective ac resistance is to be determined

= Three-phase short circuit load loss in kW at rated armature current SCLP

aT = Average temperature of the armature winding in degree Celsius during short circuit load loss test

Rated line current, Amps

3 x V

Sx 10 I

LB

TB3

LB = (1)

Base impedance, Ohm S)(V

ZTB

2LB

B = (2)

Ohm F) (T

F)(T x R R S

Tdc,TSdc, ++

= (3a)

Ohm F) (T

F)(T x R R a

Tdc,Tadc, ++

= (3b)

where, F = 234.5 for copper conductor, and F = 225.0 for aluminum conductor.

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Stray load loss, (4) Watt ]xR)[3(I -10 x P P Tadc,

2LB

3SCLSLL =

p.u. Z

)3(I

P R

RB

2LB

SLLTsdc, +

= (5)

Calculation of Unsaturated Direct-Axis Synchronous Reactance duX

( )air,Lair,f V,I = Any non-zero point on the air-gap line, where is the field current in amperes and is line voltage in kV

air,fI

air,LV

fscI = Field current in amperes corresponding to the rated short circuit current. = /(S.C. current in pu corresponding to ) duX pu,air,LV air,fI

p.u. I x V I x V

Xair f,LB

fscair L,du = (6)

Calculation of Short Circuit Ratio (SCR) Additional variables for Short Circuit Ratio:

frvI = Field current in amperes corresponding to the rated voltage on the Open Circuit Characteristic.

SCR = (7) fscfrv I/I Calculation of Saturated Direct-Axis Synchronous Reactance, Potier Reactance (Xp) and Saturation Factor (SFi)

( )Lzpffzpf V,I = Specifies the zero power factor test data where is the field current in

amperes to give rated current and a line voltage in kV at zero-power factor.

fzpfI

VLzpf

( )1Lfl V,I , ... , = The points, specified in ascending order of field current at suitable

intervals, where is the field current in amperes corresponding to the line voltage in kV.

( LNfN V,I )fiI

LiV

Note: The program approximates the Open Circuit Characteristic specified through N points by linear segments joining these points.

In the (field current - Line voltage) plane, AA is defined to be a line passing through ( )Lzpffscfzpf V,II − and parallel

to the air-gap line. With as the point of intersection of this line with the Open Circuit Characteristic (field current in A, and line voltage in kV),

( Lofo V,I )

= pX ( )pu,Lzpfpu,Lo VV − p.u. (8)

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Saturation factors and saturated direct-axis synchronous reactance are computed for the open circuit line voltages (also, resultant air-gap line voltages), ( N,1i,VLi )= and . For the ith line voltage on the Open Circuit Characteristic :

LoV iV

Resultant air-gap voltage in p.u., = (9a) i,LAV LBi V/V Saturation factor, = (9b) iSF ii,air,L V/V

p.u. SF

X - X X X

i

pdu Pids, += (9c)

where is the line voltage in kV on the air-gap line corresponding to the field current for line voltage in kV on the Open Circuit Characteristic;

i,air,LV iV

Calculation of Quadrature-axis Synchronous Reactance From Slip Test For quadrature-axis synchronous reactance (for salient-pole machines): = Respectively maximum and minimum line currents in amperes minmax I,I = Respectively maximum and minimum line voltages in kV minmax E,E

Method 1 p.u. I x V

Ix E X

maxLB

LBminq = (10)

Method 2 ( )( ) .u.pI/IE/EXX maxminmaxminduq = (11)

Where, is calculated using equation (1) and VLB is the machine rated voltage in kV. LBI

It may be noted that the best result is obtained by using Method 2. Calculation of Quadrature-axis Synchronous Reactance From Maximum Lagging Current Test

E = Line voltage in kV I = Line current in amperes at stability limit.

= p.u. (12) qX pupu I/E

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Longhand Calculation For Program Verification and Validation / QA/QC

Example:

= 0.22 kV LBV

TBS = 0.045 MVA Conductor material: Copper = 0.0335 ohm at T= C dcR °25 = 2.0 kW at SCLP C30Ta °=

sT = C20° = 1.8 A air,fI = 0.1653 kV air,LV = 2.2 A fscI = 2.84 A frvI = 0.22 kV LzpfV

= 5.8 A fzpfI Open Circuit Characteristic:

Field Current (A) Line Voltage (kV) 0.6 0.0551 1.2 0.1102 1.8 0.158 2.4 0.197 2.84 0.220 3.4 0.244 3.8 0.258 4.4 0.275 4.8 0.285 5.4 0.297 6.0 0.308 6.8 0.321

Slip test data: = 0.145 kV maxE = 85 A minI = 0.108 kV minE = 112 A maxI Maximum lagging current test data: E = 0.144 kV I = 162 A

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Solution : Rated line current (also, the base line current) = 118.094373 A, by eq.(1) Base impedance, = 1.075556 ohm by eq.(2) BZ

sdc T,R = 0.032855 ohm by eq.(3a)

adc T,R

= 0.034145 ohm by eq.(3b) Stray load loss, = 571.393043 W by eq.(4) SLLPEffective AC resistance, R = 0.043244 p.u. by eq.(5) A: Unsaturated direct-axis synchronous reactance, = 0.918333 p.u. by eq.(6) duX B: Short circuit ratio = 1.290909 by eq.(7) Point of intersection of line AA with the Open Circuit Characteristic: = 4.1091864 A foI = 0.26675 kV LoV C: = 0.2125 p.u. by eq.(8) pX Using eqs.(9a,b,c):

Resultant Air-gap Voltage in p.u.

Saturation Factor

Saturated Direct-axis Synch. Reactance in p.u.

0.25045 1.0 0.918333 0.5009 1.0 0.918333 0.71818 1.0462 0.88716 0.89545 1.118782 0.84339 1.0 1.185485 0.80789 1.109091 1.279643 0.76408 1.172727 1.352585 0.73434 1.2125 1.414659 0.71144 1.25 1.469335 0.69287 1.295454 1.546667 0.66885 1.35 1.669697 0.63523 1.4 1.788961 0.60704 1.459091 1.945379 0.57532

Quadrature-axis synchronous reactance: From slip test, Method 1: Xq = 0.48886 p.u. by eq.(10) D: Method 2: Xq = 0.49026 p.u. by eq.(11) From maximum lagging current test, E: Xq = 0.47714 p.u. by eq.(12).

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Getting Started

In the following paragraphs, several Calculation windows are shown with example data. The machine used for these example screens is a design class A, 220 Volt, 45 kVA, 1200 rpm salient pole machine. This example is also referenced in the Longhand Calculations. Opening or Creating a File

From the main menu select “Analysis/Rotating Machine Parameters/Synchronous Machines Param” After starting Synchronous Machine Parameter Calculation, the first thing you need to do is either create a new project file, or open an existing one. This is done via the File|Open or File|New command shown below.

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Either creating, or opening a file, the Machine ID view (shown below) is opened. From the main menu select “New”.

This view will be blank if you have created a new file. This is the form where machines are described. Each machine in your project file must have a unique Machine ID. Beyond that, there are very few restrictions upon what may go into the ID and description fields. Rated voltage and kVA are input here since these values are required by all calculations. At this time minimize the screen (do not quit).

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Opening Calculation Views The importance of the program is in the Calculation views that are accessed by the Calcs menu illustrated below:

The various Synchronous Machine Parameter calculations are largely independent of each other, so input parameters and results have been organized in a single view for each calculation. The calculations options are: 1. Calculation of AC resistance 2. Calculation of D-axis reactance and SCR 3. Calculation of D-axis saturated reactance 4. Calculation of Quadrature-axis reactance, using Slip test method 5. Calculation of Quadrature-axis reactance, using Maximum Lagging Current test method Note: In order to use any of the Calcs commands, a machine parameter file must be open.

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Calcs|AC Resistance The Calcs|AC Resistance command opens an AC resistance calculation view for the active machine parameter file.

he input data fields in this calculation view are described below:

T

Armature Conductor Material Select either copper or aluminum. This affects the characteristic re for resistance calculations.

DC resistance of the armature per Y-

elsius at which the

SC Load Loss - kW at Rated Armature Current

Enter the 3-phase short circuit load loss in kW at rated armature current.

SC Load Loss - Temp, C

Enter the average temperature of the armature winding during short circuit load loss measurement in degrees Celsius.

Operating temp, C Enter the operating temperature at which AC resistance is to be calculated.

temperatu

DC Resistance - Ohms/ Enter the published or measuredY-phase phase in ohms.

DC Resistance - temp, C Enter the armature winding temperature in degrees CDC resistance measurement was taken.

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Calcs|D-Axis X/SCR The Calcs|D-Axis X/SCR command opens a Direct-axis unsaturated reactance / short-circuit-ratio calculation view for the active machine parameter file. The input data fields in this calculation view are described below:

rt R

ld ps. ge, V. This field is repeated on the D-Axis Saturated X

Air-gap Data Point Line ap line. Enter line voltage in Volts. X

SC .

Voltage c

he

is checked.

Optional Calculation Check the Short Circuit Ratio (SCR) box if you want to calculate shocircuit ratio. This opens an additional input field that is required for SCcalculation.

Air-gap Data Point - FieCurrent

Enter any non-zero point on the air-gap line. Enter field current in amSee line-voltacalculation view.

Enter any non-zero point on the air-gVoltage, V See field current. This field is repeated on the D-Axis Saturated

calculation view.

Field Current at Rated Current

Enter the field current in amps corresponding to the rated short circuit current. This field is repeated on the D-Axis Saturated X calculation view

Field Current at Rated on OC Characteristi

Enter the field current in amps corresponding to the rated voltage on tOpen Circuit Characteristic. This field is activated when the Short Circuit Ratio box

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Calcs|D-Axis Saturated X The Calcs|D-Axis Saturated X command opens a direct-axis saturated reactance calculation view for the active machine parameter file. The input data fields in this calculation view are described below.

ield Current

El v

Ef

ET

Rated current, Zero PF Field E ent in amps to give rated line current and a specified line v

rent, Zero PF Line E e r

Tc ints. Click the Add button to open the Open Circuit Characteristic dialog to add a data point.

Points are automatically ordered by increasing field current, regardless of the order in which they are entered. Up to 100 points may be used to describe the Open Circuit Characteristic.

Air-gap Data Point - F nter any non-zero point on the air-gap line. Enter field current in amps. See ine-voltage, V. This field is repeated on the D-Axis X / SCR calculationiew.

Air-gap Data Point Line Voltage, V

nter any non-zero point on the air-gap line. Enter line voltage in Volts. See ield current. This field is repeated on the D-Axis X / SCR calculation view.

Field Current at Rated SCCurrent

nter the field current in amps corresponding to the rated short circuit current. his field is repeated on the D-Axis X / SCR calculation view.

nter the field currCurrent

Rated cur

oltage at zero power factor.

nter the line voltage corresponding to the specified field current to givVoltage

Open Circuit Data Add

ated line current at zero power factor.

he machine’s Open Circuit Characteristic is defined by a series of field-urrent, line-voltage po

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Open Circuit Data Delete Click the Delete button to delete the currently highlighted Open Circuit

Open Circuit Data Edit Click the Edit button to open the Open Circuit Characteristic dialog to change a data point.

Open Circuit Characteristic - Data Point Dialog The Open Circuit Characteristic - Data Point dialog is executed in response to either the Add or Edit command buttons on the D-Axis Saturated X calculation view. The input data fields in dialog are described below:

Characteristic data point.

Field Current Enter the open circuit field current in amps for a corresponding line voltage.

Line Voltage Enter the line voltage in Volts corresponding to the specified field current.

Calcs|Q-Axis X (1) The Calcs|Q-Axis X (1) c and opeactive m eter file. This calculationunsaturated direct-axis reactance calcu n performed for the machine. If there is no valid unsaturated r culation t w appears

ommachine param

ns a quadrature-axis reactance, slip-test method, calculation view for the can take one of two forms, depending on whether a valid

lation has beeeactance calculation, the calhis case, the calculation vie

uses maximum line current and minimum line voltage of the slip test data. In as follows.

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15


The input data fields in this calculation view are described below: Line Current - Minimum Enter the minimum line current from the slip test.

Line Current - Maximum Enter the maximum line current from the slip test.

Line Voltage - Minimum Enter the minimum line voltage from the slip test.

Line Voltage - Maximum Enter the maximum line voltage from the slip test.

Calcs|Q-Axis X (2) The Calcs|Q-Axis X (2) command opens a quadrature-axis reactance, maximum-lagging-current-test method, calculation view for the active machine parameter file. The input data fields in this calculation view are described below.

Line current Enter the line current in amps at the stability limit.

Line voltage Enter the line voltage in Volts at the stability limit.

Getting Results As soon as the program detects valid inputs, the calculation is updated. If invalid data are entered into an input field, the calculation window is immediately blanked.

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Closing Views To close a Calculation view, select the ou want to close. The

ny other in the upper left corner of llustrated

Close command from the system menu for the view ysystem menu for a view (or athe view’s window. This is i

window) is accessed by clicking the small gray box below:

If you close the Machine ID view, all other views of the associated project file are also closed. This has the same effect as selecting the File|Close command.

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Saving the File

To save the file, from the main menu select “Save”

Enter file name “Tutorial.smp” and press .

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The Toolbar

Single button short-cuts for several of the menu commands are provided on the toolbar. Command equivalents for the toolbar buttons illustrated above are as follows, from left to right: File|New Create a new document File|Open Open an existing document File|Save Save this document Edit|Cut Cut the record into a buffer Edit|Copy Copy the record into a buffer Edit|Paste Paste a record from the buffer Edit|Undo Undo the last action Record|First Record|Prev Record|Next Record|Last File|Print

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Command Reference

ile Commands F

New The File|New command opens a new, untitled machine parameter file, and opens a e ID view of the file. The application prompts you to give a name to an

it is closed.

|Open command displays the Open a File dialog box so you can select an arameter file to load. You can also create a new file by giving it a rrently exist.

The default directory for opening existing files is defined in the EDSAMPRM.INI file in your Windows directory.

The File|Close command checks to see if unsaved changes have been made to the active machine parameter file. If there are unsaved changes, the option is provided to save or discard the changes. All view windows for the file are then closed.

Save The File|Save command saves the machine parameter file in the active view window to disk. If the file is unnamed, the Save/File As dialog box is displayed so you can name the file, and choose where it is to be saved.

Save As The File|Save As command allows you to save a file under a new name, or in a new location on disk. The command displays the Save/File As dialog box. You can enter the new file name, including the drive and directory. All view windows containing this file are updated with the new name. If you choose an existing file name, you are asked if you want to overwrite the existing file.

blank Machinuntitled file when

Open The Fileexisting machine pname that doesn't cu

Close

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Output The File|Output command allows you to save records as a text file.

The File|Print command generates a formatted report of all input and results for the active machine parameter file, and spools it to the default windows printer, or to the printer selected under the Print Setup command.

Print Setup The File|Print Setup command displays the Windows printer setup menu. Printer

settings may be changed, or a printer other than the default may be selected. Settings will only affect printout generated by the machine parameter calculation program.

Exit The File|Exit command ends the machine parameter program session. If changes have been made since the file was saved, options are provided to save the changes, discard the changes or cancel the Exit command.

Edit Commands

Print

used to manipulate text in the various data input and result fields of the The Edit commands can be machine p ter calculation progra

Edit|Undo it|Cut, Edit|Paste or Record|Delete.

Edit|Copy

arame m.

Reverse the action of the last command: Ed

Edit|Cut Cut the machine record and put it on the clipboard and data buffer. Select Edit|Undo or Edit|Paste command to reverse this action, if necessary. Copy the machine record and put it on the clipboard and data buffer.

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R mmands

ecord Co

Multiple machines are managed by the Synchronous Machine Parameter Calculation program within a single file. Each machine occupies a “record” within the file. The Record commands provide for navigation through and manipulation of the various machine parameter records in a file. Records within the file are always alphabetically sorted according to the Machine ID assigned to it.

Record|First Move to the first machine record.

Record|Prev Move to the previous machine record.

Record|Next Move to the next machine record.

Record|Last Move to the last machine record.

Record|Insert Open a blank machine record in the active file.

command to reverse this action if necessary.

Record|Delete Delete the currently displayed record from the active file. Select Edit|Undo

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Clipboard Commands

The Clipboard menu provides command to output text data from a machine record. This command will make a user

the text to Clipboard.

indow Commands

easily bind synchronous machine parameters in a documentation or text file.

Export The Clipboard|Export command converts a printing formated data to text data, and then copies

W

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Wwind

indow commands provide control over the arrangement of calculation View Windows within the application ow area.

Cascade The Window|Cascade command sizes all View Windows at their normal size, and arranges them so that the captions of all View Windows are visible.

Tile The Window|Tile command sizes all View Windows to an equal size so that they can be arranged in a tile pattern within the application Window area.

Arrange Icons The Window|Arrange Icons arranges the icons for any minimized Windows (see System Menu) in a row at the bottom left of the application Window area.

Close All The Window|Close All command closes all Window Views. This is equivalent to selecting the File|Close command.

1 (etc.) Each open window or calculation view will have an entry in the Window menu. Selecting one of these entries will bring that view to the top of the stack of View Windows in the application area.

Help Commands

Help commands provide access to on-line information designed to help you use the Machine Parameter Calculation program.

Contents Displays the master table of contents for the Help system.

24


Using help Displays general information about how to use the Help system.

About Displays information about the program, including version ID and copyright notice.

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Output Results E chronous Machine I le: D:\EDSA_VV\SYOutput File: C:\EDSA\OUTPUT\TUTORIAL.txt ate:

Machine ID: TUTORIA 45 kVA, 220 Volts 1200 RPM, 60 Hz Machine Rating Voltage: 220 kVA: 45 Input Machine Parameters DC Resistances Ohms/Y-phase: 0.0355 at temp: 25.0 C Short Circuit Load Loss KW at rated armature current: 2.0000 at temp: 30.0 C Operating Temp: 20.0 C Air-gap data point Field Current:1.80amp Line Voltage:165.30volts Field Current At rated short circuit current: 2.20 At rated voltage on open circuit characteristic: 2.84 Rated Current,zero PF data point Field Current:5.80amp Line Voltage:220.00volts Slip Test Data Minimum Maximum Line Current: 85.00 112.00 Line Voltage: 102.00 145.00 Maximum Logging Current Test Data Line current:162.00amp Line voltage:144.00volts at stability limit. Calculated Machine Parameters Effective AC Resistance: 0.0432 p.u. (0.0464 ohms) Unsaturated Sync Reactance: 0.9183 p.u. (0.9877 ohms) Short Circuit Ratio: 1.291 Potier Reactance from Zero PFTest: 0.2125p.u. (0.2286 ohms) Q-Axis Sync X from Slip Test: 0.4903 p.u. (0.5273 ohms) Q-Axis X from Max. Lagging Cur Test: 0.4771 p.u. (0.5132 ohms) Saturated Direct-axis Reactance Fld Current Line Voltage Air-Gap V Sat Factor X-p.u. X-ohms 0.60 55.1 0.250 1.000 0.918 0.988 1.20 110.2 0.501 1.000 0.918 0.988 1.80 158.0 0.718 1.046 0.887 0.954 2.40 197.0 0.895 1.119 0.843 0.907 2.84 220.0 1.000 1.185 0.808 0.869 3.40 244.0 1.109 1.280 0.764 0.822 3.80 258.0 1.173 1.353 0.734 0.790 4.11 266.8 1.213 1.415 0.711 0.765 4.40 275.0 1.250 1.469 0.693 0.745 4.80 285.0 1.295 1.547 0.669 0.719 5.40 297.0 1.350 1.670 0.635 0.683 6.00 308.0 1.400 1.789 0.607 0.653 6.80 321.0 1.459 1.945 0.575 0.619 Note:

DSA Synnput Fi

Parameter Estimation NCH\TUTORIAL.SMP

D

If the field current is not entered by the user, EDSA will calculate this value (bolded text for this example). PROGRAM RESULTS AND LONGHAND CALCULATIONS MATCH 100% PROGRAM LONGHAND % DEVIANCE A 0.9183 0.9183 0%

B 1.291 1.290909 0%

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C 0.2125 0.2125 0%

.49026 0%

0.47714 0%

D 0.4903 0

E 0.4771

27


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References

1. Fitzgerald, A. E., and Kin Jr., gsley, C., inery''Electric Mach , M ew York, 1961.

2. IEEE Guide : Test Procedures For Synchronous Machines

cGraw-Hill, N

, IEEE Std 115-1983. 3. Mablekos, V. E., 'Electric Machine Theory For Power Engineers', Harper & Row, New York,

1980.

4. Matsch, L. W., and Morgan, J. D., 'Electromagnetic And Electromechanical Machines', Harper & Row, New York, 1986.

Edsa Paladin

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