Instruction manual
–
AQ G3x7 Generator protection IED
29 (211
)
3.2
P
ROTECTION
F
UNCTIONS
3.2.1
G
ENERATOR DIFFERENTIAL
I
D
G>(87G)
The generator differential protection function provides main protection for generators or large
motors. The application needs current transformers in all three phases both on the network side
and on the neutral side.
The inputs are
•
the sampled values of three phase currents measured at the network side,
•
the sampled values of three phase currents measured at the neutral connection,
•
parameters,
•
status signals.
The outputs are
•
the binary output status signals,
•
the measured values for displaying.
The software modules of the generator differential protection function:
Diff base harm.
This module calculates the basic Fourier components of the three differential currents. These
results are needed also for the high-speed differential current decision.