Landis+Gyr E650 Series 4 User Manual page 26

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Losses
© Landis+Gyr
Depending on the metering point in the network, the meter does not only
measure the net energy that is transferred from the power station to the
user but also the line losses (caused by the copper resistance R
transformer losses (caused by the iron resistance R
Metering point A
Generator
Production Meter A
Figure 17. Calculation of losses
Line losses are caused by the copper resistance R
line. The copper resistance is only effective if there is a load and therefore
current is actually flowing.

On Load Active OLA for line losses of active energy
The transformer losses represent all losses of the transformer. They are
mainly caused by the iron core of the transformer. Transformer losses
(equivalent resistance R
connected to the network.

No Load Active NLA for transformer losses of active energy
Based on the I and U
RMS
following measured quantities:
OLA On load active. Line (copper) losses of active energy.
2
OLA = I
No load active. Transformer (iron) losses of active energy.
NLA
NLA = U
2
I h (Cu)
Ampere square hours (with R
2
U h (Fe)
Voltage square hours (with R
It is also possible to track signed losses (±NLA/OLA). If this option is
chosen, NLA and OLA losses are not available any more as these registers
are used for signed losses.
D000062026 en a – E650 Series 4 – ZMD400AT/CT, ZFD400AT/CT – User Manual
Metering point B
R
Cu
Transmission
) are present whenever the transformer is
Fe
values, the microprocessor generates the
RMS
h x R . The value of R
Cu Cu
2
h / R . The value of R
Fe Fe
= 1)
Cu
1 M)
Fe
Device description
) and the
Cu
).
Fe
Metering point C
R
Fe
Load
Meter B Customer
of the transmitting
Cu
can be set by parameterisation.
can be set by parameterisation.