Instruction manual
–
AQ G3x7 Generator protection IED
10 (211
)
IMP21
Z<
21
Underimpedance protection
PS78
PS
78
Pole slip
UEX40Z_low
UEX40Z_high X<
40
Loss of field/loss of excitation
VPH24
V/Hz
24
Overexcitation/Volts per hertz
BRF50MV
CBFP
50BF
Breaker failure protection
Table 3-2 Control and monitoring functions of AQ-G357
Name
IEC
ANSI Description
TRC94
-
94
Trip logic
DLD
-
-
Dead line detection
VTS
-
60
Voltage transformer supervision
SYN25
SYNC
25
Synchro-check function
Δ
f,
Δ
U,
Δφ
Sag&Swell
-
-
Voltage sag and swell monitoring
DREC
-
-
Disturbance recorder
3.1
M
EASUREMENT FUNCTIONS
3.1.1
C
URRENT MEASUREMENT AND SCALING
If the factory configuration includes a current transformer hardware module, the current
input function block is automatically configured among the software function blocks.
Separate current input function blocks are assigned to each current transformer hardware
module.
A current transformer hardware module is equipped with four special intermediate current
transformers. As usual, the first three current inputs receive the three phase currents (IL1,
IL2, IL3), the fourth input is reserved for zero sequence current, for the zero sequence
current of the parallel line or for any additional current. Accordingly, the first three inputs
have common parameters while the fourth current input needs individual setting.
The role of the current input function block is to
•
set the required parameters associated to the current inputs,
•
deliver the sampled current values for disturbance recording,
•
perform the basic calculations
o
Fourier basic harmonic magnitude and angle,
