Figure. 5.4.8. - 92. TRF function outputs activation.
“No load” signal is activated when the current is under “No load current” limit (0.2 xIn)” for more than
10 ms time. If the current increases from this situation to “Heavy overloading limit (> 1.3 x In) then
“HV/LV inrush detection” signals are activated. If measured current is in between of low detection and
nominal current the “Load normal” signal is activated. If measured current is in between of nominal and
heavy overloading current “Overloading” signal is activated.
These signals can be used for informational and also for transformer related logics and monitoring
usage. For example constant long duration heavy overloading may cause the transformer oil ageing
and thus the maintenance should be applied before scheduled in order to prevent possible problems in
the transformer.
Settings and signals
Settings of the transformer status monitor (TRF) function are mostly shared with transformer protection
functions in the transformer module of the IED. In following table are shown the functions which use
these settings also.
Table. 5.4.8. - 64. Settings of the TRF function.
Name
Range
Step
Default
Funcs.
Description
Transformer
nominal
MVA
0.1...500.0MVA 0.1MVA 1.0MVA
All
Nominal MVA of transformer. This value is used to
calculate nominal currents of HV, and LV side.
HV side
nominal
voltage
0.1…500.0kV
0.1kV
110.0kV
All
HV side nominal voltage of the transformer. This value
is used to calculate nominal currents of HV side.
LV side
nominal
voltage
0.1…500.0kV
0.1kV
110.0kV
All
LV side nominal voltage of the transformer. This value
is used to calculate nominal currents of LV side.
Transformer
Zk%
0.01…25.00%
0.01%
3.00%
Info
Transformer short circuit impedance in %. Used for
calculation of the short circuit currents
AQ-T216
Instruction manual
Version: 2.00
111
© Arcteq Relays Ltd