Electro Industries/GaugeTech Nexus 1250, Installation & Operation Manual

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Electro Industries/GaugeTech
Doc #: E107-6-07-121
7-1
Chapter 7 Chapter 7
Transformer Loss Compensation Transformer Loss Compensation
7.1: Introduction 7.1: Introduction
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The Edison Electric Institute’s Handbook for Electricity Metering, Ninth Edition defines Loss
Compensation as:
A means for correcting the reading of a meter when the metering point and point of service are
physically separated, resulting in measurable losses including I
2
R losses in conductors and
transformers and iron-core losses. These losses may be added to or subtracted from the meter
registration.
n
Typically, meters connected to secondary circuits cannot measure power dissipated in transmission
lines and in the cores of transformers. Transformer Loss Compensation (TLC) is a technique that
electrically or computationally accounts for the lost active and reactive power. These calculations are
based on the formulas below. These equations describe the amount of active (Watts) and reactive
(Vars) power lost due to both iron and copper effects (reflected to the secondary).
•
Vars Compensation =
((Measured Voltage/Cal point Voltage)
4
x %LVFE x Secondary VA) + ((Measured Current/Cal
Point Current)
2
x %LVCU x Secondary VA)
•
Watts Compensation =
((Measured Voltage/Cal point Voltage)
2
x %LWFE x Secondary VA) + ((Measured Current/Cal
Point Current)
2
x %LWCU x Secondary VA)
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These compensation values are added to the measured Watts and Vars for delivered power and
subtracted from the same quantities for received power. The Values for %LWFE, %LWCU, %LVFE,
%LVCU are derived from the transformer and meter information, as demonstrated in following
sections.
Courtesy of NationalSwitchgear.com