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A1700 Programmable Polyphase Meter
Chapter 2 - Overview
M120 001 2S
5.2007
A1700 Chapters Chapter 1 Introduction M120 001 1 Chapter 2 Over
view M120 001 2 Chapter 3 Hardware M120 001 3 Chapter 4
Communications M120 001 4 Chapter 5 Input/Output M120 001 5 Chapter
6 Installation M 120 0016
Chapter 7 Software Support M120 001 7 Chapter 8 IEC 870 Meter
(Special) M120 001 8 Chapter 9 T. L. Compensation (Special) M120
001 9
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A1700 Meter Users Manual - Chapter 2 1
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CONTENTS
1 POWER AND ENERGY MEASUREMENT
............................................................................
2
2 PRINCIPLES OF ENERGY MEASUREMENT
.......................................................................
3
2.1 Energy Measurement
..............................................................................................................
3 Figure 1 3-Phase 4-Wire System
..........................................................................................
3 Figure 2 3-Phase 4-Wire Vector
Diagram.............................................................................
3 2.2 Apparent Energy Measurement
..............................................................................................
4 2.3 Reactive Energy Measurement
...............................................................................................
4 2.4 Four Quadrant Metering
..........................................................................................................
5 Figure 3 Four Quadrant
Measurement..................................................................................
5 2.5 Network
Application.................................................................................................................
5 3-Phase 3-Wire
.......................................................................................................................
6 Figure 4 3-Phase 3-Wire System
..........................................................................................
6 3-Phase 4-Wire
.......................................................................................................................
6 Figure 5 3-Phase 4-Wire System
..........................................................................................
6 2-Phases of 3-Phase 4-Wire
...................................................................................................
7 Figure 6 2-Phases of a 3-Phase 4-Wire
System...................................................................
7 1-Phase
3-Wire........................................................................................................................
7 Figure 7 1-Phase 3-Wire System
.........................................................................................
7 1-Phase
3-Wire........................................................................................................................
8 Figure 8 1-Phase 3-Wire System
.........................................................................................
9 1-Phase
2-Wire........................................................................................................................
8 Figure 9 1-Phase 3-Wire System
.........................................................................................
9
3 TARIFF
APPLICATIONS........................................................................................................
9
3.1 General
....................................................................................................................................
9 3.2 Tariff Features
.......................................................................................................................
10 Billing Date
............................................................................................................................
10 Billing
Period..........................................................................................................................
10 End of Billing Period
..............................................................................................................
10 Time of Use Registers
...........................................................................................................
10 Switching Times
....................................................................................................................
10
Seasons.................................................................................................................................
11 Integration Period
..................................................................................................................
11 Average
Demand...................................................................................................................
11 Maximum Demand
................................................................................................................
11 Block Interval Demand
..........................................................................................................
11 Sliding Window Demand
.......................................................................................................
11 Cumulative Registers
............................................................................................................
12 Cumulative Maximum Demand
.............................................................................................
12 Total kVAh
.............................................................................................................................
12 Customer Defined Registers
.................................................................................................
12 3.3 Time Keeping
........................................................................................................................
13 3.4 Data Logging
.........................................................................................................................
13
4 CONFIGURATION, COMMUNICATION AND DATA
COLLECTION.................................. 14
4.1 General
..................................................................................................................................
14 4.2 Support Systems
...................................................................................................................
14 Figure 10 Total System Capability
........................................................................................
14 Power Master Unit
Software..................................................................................................
15 CHIRPS
.................................................................................................................................
15 Figure 11 - CHIRPS Overall
Concept....................................................................................
16
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Overview
1 POWER AND ENERGY MEASUREMENT Electrical Power in any system of
n conductors may be measured by the algebraic sum of (n-1)
wattmeters. This is known as Blondel's Theorem. It derives from the
fact that the power in each of the conductors is measured with a
current sensor that determines the current, and a voltage sensor,
which measures the potential of the conductor relative to a common
point.
If the common point of the voltage measurement is made one of
the conductors, one of the wattmeters will read zero and can
therefore be omitted.
If the word "power" is replaced by "energy", "wattmeter" by
"watt-hour" meter, the theorem is applicable to energy
measurement.
In the A1700, analogue to digital converters, fed by sensors,
determine the voltage measurements. These replace the conventional
current and voltage coils of electromechanical meters.
There are some installations where (n-1) meter elements are not
used. For economical and installation reasons, forms of watt-hour
meters having fewer than (n-1) meter elements are considered
satisfactory where the compromise still permits metering accuracy
well within good commercial practice. For example, in some cases it
is assumed that the voltages are approximately balanced. In others
the load is assumed to be connected only between certain wires.
If a system is grounded and the ground lead not connected into
the service installation, the ground still constitutes one of the n
conductors. For example a 3-phase 4-wire system with earth neutral
may be used at some location with only the three phase wires.
Applying the theorem to the metering service, it must be considered
as a 4-wire system.
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2 PRINCIPLES OF ENERGY MEASUREMENT
2.1 Energy Measurement The principles involved in measuring
energy using the A1700 meter can be described by considering a
3-phase 4-wire circuit. Figure 1 shows a typical arrangement for a
CT operated meter.
A1700
Va VcVb
Ia
Ia
Ib
Ib
Ic
Ic
Za
Zb
Zc
A
B
C
N The vector diagram (Figure 2) shows the relationship between
the phases. Note: safety earths are omitted
Figure 1 3-Phase 4-Wire System
Figure 2 3-Phase 4-Wire Vector Diagram V
A IA
, VB
IB
and VC
IC
are phasors representing sinusoidal quantities.
The total power at any instant is given by: P = va ia + vb ib +
vc ic, where v and i are instantaneous values at time t, and the
total energy is the integral of power with time.
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Expressed mathematically this is:
T2
E = Pdt T1 The current and voltage waveforms are close to being
sinusoidal and the more well known expression for power is given as
P = VAIA cos A + VBIB cos B + VCIC cos B CV and I are the r.m.s.
values of voltage and current = Phase displacement between
them.
The way in which the meter derives its power measurement is to
measure digitally at discrete intervals the voltage and current on
each phase. The product of these measurements and the period of the
discrete time interval give the energy value. These discrete energy
values are accumulated into a total energy register. This is
sometimes referred to as the real energy measurement and is
registered Watthours or kiloWatthours.
2.2 Apparent Energy Measurement A quantity often required for
tariff purposes is apparent energy or Volt Amp hours (VAh).
Apparent energy is derived by multiplying the r.m.s. voltage and
the r.m.s. current values together, then integrating over time to
produce VAh.
The A1700 meter uses the same digital measurements used for the
real energy to derive the r.m.s. voltage and current and hence the
apparent energy. The Volt-Ampere measurement is a scalar quantity.
Strictly, it has no relation to phase displacement between voltage
and current. In some tariff applications it is necessary to
register the Volt-Amperes in one quadrant.
2.3 Reactive Energy Measurement An important measurement often
required as part of the energy measurement is the reactive
component. This relates to the phase difference between the voltage
and current waveforms.
At unity power factor i.e. when the current and voltage are
exactly in phase, there is no reactive energy. At zero power
factors, i.e. current and voltage are 90 phase displaced, all the
energy is reactive, there is no real power recorded.
The reactive power, or out of phase power, is often defined as
VI sin where V and I are the r.m.s. values of voltage and current,
and is the phase displacement between them.
Unlike electromechanical meters, where the standard technique is
to cross connect the voltage coils, the A1700 meter performs this
function digitally. The reactive energy is calculated on a phase
basis from the simultaneous measurement of apparent energy and real
energy. This achieves a more accurate measurement, being a true
sine measurement, and it has the advantage of being applicable to
both single and polyphase systems.
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2.4 Four Quadrant Metering The measurement techniques for real
and reactive energy employed in the A1700 meter rely on sampling
the voltage and current waveforms and multiplying these values
together with the time interval. The measurements are independent
of the phase angle and can therefore take place through a phase
difference of 360 between voltage and current. This effectively
provides 4-quadrant energy metering.
Real and Reactive energy are identified as being import or
export. In the case of reactive energy the terms lag and lead are
often used. The meter identifies in which quadrant the reactive
energy is relative to the real energy, and accumulates the
consumption in a particular register. It is therefore capable of
measuring:
Q1 kvarh Import Lagging Energy Q2 kvarh Import Leading Energy Q3
kvarh Export Lagging Energy Q4 kvarh Export Leading Energy
The relative positions of these are as shown in the figure
below.
Figure 3 Four Quadrant Measurement
2.5 Network Application Polyphase meters in general contain
either two or three measuring elements. The number of measuring
elements a polyphase meter has is determined by the network to
which it is to be applied.
The following are examples of the more common applications in
power networks. For other applications, contact Elster Metering
Systems.
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2.5.1 3-Phase, 3-Wire Two element meters are used for
applications with line to line voltage applied across the voltage
sensor and line currents through the current sensor. The circuit
and vector diagrams are shown below.
VAB
VBC
VA
VAB
VCB
VC
IA IA
IB
ZAB
ZCB
ZAC
IC
IC
IA
A
B
C
1
2
Figure 4 3-Phase 3-Wire System P = VAB IA cos (30 + 1) + VCB IC
cos (30 - 2)
2.5.2 3 Phase, 4 Wire In a 3-phase 4-wire system, three elements
are required for accurate measurement. This equates to three single
phase meters. The circuit and vector diagrams are shown below.
VAN
VBN
Ic
IA
IB
IA
IB
ZA
ZB
IC
VCN
A
B
C
N
VAIA
IC
VC
VB
C
Figure 5 3-Phase 4-Wire System P = VAN.IA.cosA + VBN.IB.cosB +
VCN.IC.cosC
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2.5.3 2-Phases of 3-Phase, 4-Wire
In a 2-phases of a 3-phase 4-wire system only two elements are
required for accurate measurement. The circuit and vector diagrams
are shown below.
VANVAN
VCN
VCN
IA
IC
IC
IC
IA
IA
ZC
ZA
A
C
N
N A
Figure 6 2-Phases of a 3-Phase 4-Wire System P = VAN.IA.cosA +
VCN.IC.cosC
2.5.4 1-Phase 3-Wire This is sometimes used in systems where a
single phase supply has a centre tapped neutral. The circuit and
vector diagrams are shown below.
VAIN
VA2N
IA1 IA1
ZA2
ZA1
IA2
IA2
A1
N N
A2
VA1N
VA2N
IA2
IA1
A1
A2
Figure 7 1-Phase 3-Wire System To meter a 1-phase 3-wire circuit
with maximum accuracy under all conditions, it is necessary to use
a two element meter. The A1700 meter uses a 2-element measurement
for this application.
Power measurement in r.m.s terms is:
P = VA1N. IA1. cosA1 + VA2N. IA2. cos A2
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2.5.5 2-Phase 3-Wire This system is used where two phases have a
common neutral. The circuit and vector diagrams are shown
below.
VAIN
VA2N
IA1 IA1
ZA2
ZA1
IA2
IA2
A1
N N
A2
VA1N
VA2NIA2
IA1
A2
A1
Figure 8 2-Phase 3-wire P = VA1N. IA1. cosA1 + VA2N. IA2. cos
A2
2.5.6 1-Phase 2-Wire Single phase measurement can be achieved in
the A1700 meter using only one element of the three elements
available.
VAIN
IA1 IA1
ZA1
A1
N
N
VA1N
IA1A1
Figure 9 1-phase 2-wire
P = VA1N.IA1.CosA1
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3 TARIFF APPLICATIONS
3.1 General Tariffs link the consumption of energy to the cost
of supplying it. In simple cases the cost per unit (kWh) is at a
flat rate throughout the billing period. In other cases, the cost
per unit varies according to the time when it is used. For these
applications the A1700 meter has many programmable features, which
allow consumption to be registered for different times of the day.
The registers associated with this are termed Time of Use (TOU) or
rate registers. In the A1700 meter there are options of 16 or 32
registers available for this purpose. They can be designated to
record kWh, kvarh, kVAh or external inputs if an input module is
fitted.
In addition to Time of Use, Maximum Demand is a measurement that
is often applied for tariff purposes. The Maximum Demand is the
largest demand occurring in a demand period during the billing
period. Typically the demand period is 30 minutes or 15 minutes. It
is also referred to as the integration period. In the case of a 30
minute demand period the average demand of electricity defined in
kW is twice the number of units (kWh) registered in the period. For
15 minute periods it is four times. The billing period is the time
between the successive issuing of accounts, typically one month.
The maximum demand is recorded in the A1700 meter for any of the
specified measurements, kW, kvar or kVA. The time and date of
occurrence is also recorded, and there are up to 8 MD registers
that can be used. These are programmable so that, if necessary, the
maximum demand can be separately defined for different time of use
periods.
There are two ways in which the MD can be derived, block
interval or sliding. When computed by the block interval method the
demand values are compared for successive integration period and
the highest value registered. For example the periods would be
00.00, 00.30, 01.00 etc.
The alternative method, sliding demand, looks at a 30-minute
period that moves throughout the day as a window. There is a
minimum slip time that must be specified to give 10 or 15 minute
blocks within the window.
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3.2 Tariff Features 3.2.1 Billing Date
The Billing Date is the date that concludes the current billing
period for use in the customer account. All the consumption during
the period is transferred to historical registers for checking
during the succeeding period. There is a specific time when the end
of the billing period occurs, usually 24.00 (midnight).
3.2.2 Billing Period
The Billing Period is the time between consecutive Billing
Dates.
3.2.3 End of Billing Period
The End of Billing Period defines the time and date when
consumption data is recorded for the Billing Period. In the A1700
meter this action can be initiated in the following ways:
By a pre-programmed date and time stored in the meter
By an external input pulse to one of the meter module inputs
Over a communications link through the serial port
Through the optical port
By pressing the sealable push button
At a change of season date
At the introduction of a deferred tariff
3.2.4 Time of Use Registers
The A1700 has the option of 16 or 32 Time of Use registers.
These registers become active or inactive when a pre-programmed
time and date is reached. When active, a designated measurement,
kWh, kvarh, kVAh or pulses from an input module (if fitted) is
accumulated into the selected register. The accumulation continues
for the active periods during the Billing Period.
The meter must be programmed to set Time of Use registers active
in accordance with the requirement of the tariffs. More than one
Time of Use register can be active at any one time.
3.2.5 Switching Times
Switching times define the times of the day when Time of Use
registers become active and inactive. These times are resolved,
usually to a 30-minute or 15-minute period i.e. the integration
period.
The meter has the capacity to store 96 switching times. It is
possible to have different tariff arrangements for different days
of the week e.g. weekday and weekend tariffs.
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3.2.6 Seasons
Tariffs schemes can vary for different periods of the year. A
period of time defined by a start date and an end date identifies a
season in which a tariff arrangement applies. This may include
daily variations. The A1700 has a maximum of 12 Seasons.
3.2.7 Exclusion Dates During a Season there may be specific days
such as public holidays on which a different tariff arrangement
applies. These days can be programmed by identification as an
exclusion date within a season. There is a maximum of 64 Exclusion
Dates.
3.2.8 Integration Period
The Integration Period is the time in which the demand is
determined. Usually this is 30 minutes or 15 minutes, but can be
any integer devisable in to 60 minutes.
3.2.9 Average Demand
This is the average power consumed in the Integration Period. It
is computed by dividing the energy consumed (kWh, kvarh, kVAh or
recorded input energy) by the Integration Period in hours.
3.2.10 Maximum Demand
The Maximum Demand is the highest demand recorded for the
specified parameter, kW, kvar or kVA, during the Billing Period.
The A1700 meter can record up to 8 Maximum Demands. For each of
these, in some versions, the second and third highest are also
recorded.
Maximum Demand can be recorded in two ways, Block Interval and
Sliding Window.
3.2.11 Block Interval Demand
The Block Interval Demand is the calculation of the demand in
non-overlapping integration periods e.g. 30 minutes.
3.2.12 Sliding Window Demand
The calculation of demand averaged over an Integration Period
which includes sub-intervals of previous demand calculations, e.g.
a 30 minute demand period with sub-intervals will be defined as
09.00 to 09.30, 09.10 to 09.40, 09.20 to 09.50 etc.
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3.2.13 Cumulative Registers The Cumulative Registers are the
total register reading of the primary values:
kWh import/export kvarh in four quadrants Q1 kvarh Import
Lagging Energy Q2 kvarh Import Leading Energy Q3 kvarh Export
Lagging Energy Q4 kvarh Export Leading Energy KVAh Input pulses
Regardless of which Time of Use register is active, the
Cumulative Register will always advance.
3.2.14 Cumulative Maximum Demand
At the end of a Billing Period the Maximum Demand is added into
a register. This is the Cumulative Maximum Demand.
3.2.15 Total kVAh
kVAh is a scalar quantity and is calculated from the total kWh
and the total kvarh over all phases. (See Figure 3).
For some particular tariff applications it is required to
determine the kVAh by using customer defined quantities. The
quadrants to be used in kVAh calculation can be selected by the
user. e.g.
Q1 Q2 Q3 Q4
kWh * *
kvarh * *
Note: Real and reactive energy for each phase is respectively
summated prior to kVAh calculation.
3.2.16 Customer Defined Registers
The quantities to be calculated are selectable by 3 customer
defined registers. Each register is programmable to accept pulses
from two (five) of the following registers:
a) kWh Total Import b) kWh Total Export c) Q1 kvarh Import
Lagging Energy d) Q2 kvarh Import Leading Energy e) Q3 kvarh Export
Lagging Energy f) Q4 kvarh Export Leading Energy g) Input 1 h)
Input 2 i) Input 3
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j) Input 4
Examples of their use are:
Register 1 Total kWh kWh Import + kWh Export (a + b)
Register 2 Total Import kvarh kvarh Lagging Import + kvarh
Leading Import (c + d)
Register 3 Total kvarh kvarh Lagging Import + kvarh Leading
Import + kvarh Lagging Export + kvarh Leading Export (c + d + e +
f)
3.3 Time Keeping A fundamental part of the A1700 meter operation
is its time keeping. To maintain accurate time it has its own clock
with calendar capability. This clock is driven from a quartz
crystal. There is an option to use the mains frequency as the basis
of the clock. In the event of a power failure the clock will
automatically resort to its crystal back up with the circuits
supported by a stand-by battery.
In many countries there is a requirement to adjust the clock for
daylight saving. This advances (in the Spring) or retards (in the
Autumn) the clock at a preset date. The meter has the capability to
perform this automatically by pre-programming these dates. The
advance and retard can be one or two hours.
3.4 Data Logging Within the A1700 meter there is an option to
store Demand Data for successive Integration Periods. The Demand
Data can originate from any of the Primary Registers or Input
Module inputs (if fitted). Primary Registers and module inputs can
also be summated, for example:
Summate Input 1 kWh with Input 3 export kWh - (Input 1 + Input
3)
Summate kWh total import with Input 1 kWh - (kWh total import +
Input 1)
The storage capacity is 450 days (with the option of 900 days)
of data from one register at 30 minute demand intervals. In normal
operation the information is extracted from the data logging store
at regular intervals, e.g. daily or weekly.
The data storage can be allocated to a number of registers.
Example 1: It is possible to store 90 days of data (450 day
version) when 5 primary registers are logged. For single register
logging, only 225 days will be available if the integration period
is 15 minutes.
Example 2: It is possible to store 180 days of data (900 day
version) when 5 primary registers are logged. For single register
logging, 450 days will be available if the integration period is 15
minutes.
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4 CONFIGURATION, COMMUNICATION AND DATA COLLECTION
4.1 General The A1700 meter is configured by programming
features from a pre-set list of options defined in the Power Master
Unit. Programming is performed through the FLAG optical port or via
an optional communications module.
The FLAG port can also be used to read from the meter for
billing purposes. Programming and Reading are performed by Hand
Held Units using an optical connector or directly, with the same
connector, from a PC.
The RS232/RS485 communications module can be used for access to
the meter over a telecommunications link from a remote point. The
telecommunications link could be GSM Network, the Public Switched
Telephone Network, a Radio Link or direct lines. The port, being a
communications link, is of primary importance for down loading
logged demand data. It can also be used for programming and reading
in the same fashion as the optical port.
There are certain hardware features and security features that
can be programmed and monitored through the communications ports.
These include relay outputs, inputs, displays, alarms and clock
time base. These add to the tariff options available to configure
the application of the meter.
4.2 Support Systems The A1700 meter has a number of peripheral
devices and software support systems, which together create the
environment for communication, programming reading and displaying
the data.
Figure 10 shows the total system capability.
GSM network A1700
Figure 10 Total System Capability
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4.2.1 Power Master Unit Software
Power Master Unit Software runs on an IBM compatible PC,
allowing the A1700 meter (or PPM) to be programmed with tariff and
hardware features. The operator is led through a menu driven
sequence of data entries, which allows the operational features of
the meter to be set up. The communications interface is either a
direct connection from the PC through the optical port using a FLAG
probe or through an intermediary device, namely a HHU or portable
computer, which is carried to site. Alternatively the connection
can be made over the selected communications medium using an
appropriate modem. The most common way this is achieved is by an
auto answer modem responding to calls over the PSTN from the
central computer. The modem can be located under the terminal cover
of the meter.
Power Master Unit Communications The Communications Server is
invoked from the Power Master Unit and allows communication with
the A1700 meter over local or remote communications links. There
are two methods of establishing communications with a meter, by
executing a Meter List or by using Quick Send via the Scheme
Editor.
The Communications Server can be installed on a remote PC,
allowing access over a network for a number of workstations. When
networked the Communications Server must be open or communications
with a meter will not be possible. The methods of communication and
the network set-up are described in the Power Master Unit Manual
(M120 001 6).
Meter List Scheduler The Meter List Scheduler is a Power Master
Unit programming tool that allows a Meter List(s) set up in the
Power Master Unit to be activated at a time scheduled by the
software. This may be immediately (at the Start Time) or deferred
(to the earliest opportunity on or after the Start Date).
4.2.2 CHIRPS When using the Hand Held Unit, a multi vendor
software package, CHIRPS, (Common Hand Held Integrated Reading and
Programming Systems) is invoked. It provides a common set of
command and data structures, which allow a variety of meters from
different manufacturers to operate with a variety of Hand Held
Units.
The overall concept is shown in overleaf.
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Figure 11 CHIRPS Overall Concept
To programme or read data from a particular manufacturer's meter
or group of meters, the user employs the software specific to that
manufacturer, to create the necessary meter schemes.
A meter scheme defines the reading and programming instructions
to be applied to a meter or group of meters. Metering schemes are
prepared by entering data into the Power Master Unit Software. This
provides in simple menu driven format in a Windows environment, a
series of data entries which define what data has to be read from
the meter, e.g. number of tariffs, maximum demands etc. and data to
be programmed into the meter e.g. tariff start and end times,
seasons etc. Details are given in Chapter 6 (Software Support) of
this manual. These instructions are formulated into CHIRPS files
automatically. CHIRPS files, Reference and Sign-On files are
generated and transferred to the Hand Held Unit.
Reference and instruction files are encrypted. The Hand Held
Unit runs CHIRPS as an operating system and is thereby capable of
interpreting these files to pass data to and from the meters. In
the case of the PPM this transfer of data from P.C. to HHU uses an
applications package referred to as OMS_TRAN.
There is a range of Hand Held Units available which run the
CHIRPS environment. Details of the suppliers are available on
request to Elster Metering Systems. Usually a user will have only
one or two suppliers of Hand Held Units. The Hand Held Units
interface to the meters on site using the FLAG probe. At any time
it is possible to have data for a variety of meters held within the
Hand Held Unit. The CHIRPS operating system will first identify the
meter manufacturer, meter type and serial number during a sign on
mode. After sign on, it will then refer to its database and select
the appropriate instructions for that particular meter and transfer
the data. The communications protocol between the HHU and the meter
is FLAG IEC 62056 - 21 (formerly IEC 61107).
In most cases the transfer of information will be automatic with
an indication at the end of the transfer that the operation is
complete. It is possible to enter a manual entry mode where data
can be entered directly from the keyboard e.g. resetting time and
date, or view registers of interest. This will be in accordance
with instructions set up on the P.C. however this option is not
currently invoked in Power Master Unit Software.
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In the majority of operations the data transferred to the meter
will be a request for meter readings. As a consequence data will be
transferred back to the Hand Held Unit. This will be identified and
stored in data files. The final transaction is to transfer meter
data held in the Hand Held Unit to the P.C. for storage and
display. This transfer takes place under the command of the Power
Master Unit Software for each group of manufacturers meters. The
information is stored as files in the P.C. in the Master Unit
directories and is available for onward transfer to a mainframe
computer for processing if the necessary file translation software
is in place. In most cases it is simply viewed and checked for
report purposes using the Master Unit Software.
The data structures within CHIRPS database are shown
opposite.
The Hand Held Unit requests a sign on when interfaced to the
meter. The meter responds with a response message. This entry level
is held in a .SOD File. There is one .SOD File per manufacturer
listing the types of meters available through CHIRPS.
Having gained entry the Hand Held Unit accesses the response and
from this matches the meter database entry using the meter
identification code. The meter database entries are held in the
.REF File, which locates each meter loaded for programming and
reading. Having located a meter database entry in the .REF File the
.INS File is referenced. This determines the actions to be
performed on a particular meter e.g. load new tariff, read data
etc. These instructions are passed to the meter using the FLAG
protocol.
The meter then responds with data or, if programme instructions
have been sent, acknowledgement of acceptance. If data is being
read it is stored in the .RES File. This stores sequential data as
requested by the instruction database with each entry identified by
the meter number. When load profile data is requested this data is
stored in a .BUD File, (Bulk data).
On return to the P.C. the data held in the .RES File and .BUD
File can be downloaded.
When assembling data in the Power Master Unit Software the
instruction files and reference files are prepared automatically by
setting up a meter list. These effectively give the reference
address for the meters to be programmed and read. The details of
programming and reading are prepared through entry data from the
set-up screens detailed in the software manual. Instructions are
passed to the meter using the FLAG protocol.
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18 A1700 Meter Users Manual - Chapter 2
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Elster Metering Limited - M120 001 2S - 5/2007
1 POWER AND ENERGY MEASUREMENT 2 PRINCIPLES OF ENERGY
MEASUREMENT2.1 Energy Measurement Figure 1 3-Phase 4-Wire
SystemFigure 2 3-Phase 4-Wire Vector Diagram2.2 Apparent Energy
Measurement2.3 Reactive Energy Measurement 2.4 Four Quadrant
Metering Figure 3 Four Quadrant Measurement2.5 Network
Application2.5.1 3-Phase, 3-Wire Figure 4 3-Phase 3-Wire
System2.5.2 3 Phase, 4 Wire Figure 5 3-Phase 4-Wire System2.5.3
2-Phases of 3-Phase, 4-WireFigure 6 2-Phases of a 3-Phase 4-Wire
System2.5.4 1-Phase 3-Wire Figure 7 1-Phase 3-Wire System 2.5.5
2-Phase 3-Wire Figure 8 2-Phase 3-wire2.5.6 1-Phase 2-Wire Figure 9
1-phase 2-wire
3 TARIFF APPLICATIONS3.1 General 3.2 Tariff Features3.2.1
Billing Date3.2.2 Billing Period3.2.3 End of Billing Period3.2.4
Time of Use Registers 3.2.5 Switching Times 3.2.6 Seasons3.2.8
Integration Period3.2.9 Average Demand3.2.10 Maximum Demand3.2.11
Block Interval Demand3.2.12 Sliding Window Demand 3.2.13 Cumulative
Registers3.2.14 Cumulative Maximum Demand3.2.15 Total kVAh3.2.16
Customer Defined Registers
3.3 Time Keeping3.4 Data Logging
4 CONFIGURATION, COMMUNICATION AND DATA COLLECTION4.1 General4.2
Support Systems Figure 10 Total System Capability 4.2.1 Power
Master Unit Software4.2.2 CHIRPS
Figure 11 CHIRPS Overall Concept