Figure. 5.3.19 - 169. Simplified function block diagram of the U03rd> function.
Measured input
The function block uses analog voltage measurement values for 3
rd
harmonic voltage measurement
and three-phase current measurement values for positive sequence current blocking. A -20 ms
averaged value of the selected magnitude is used for pre-fault data registering.
Table. 5.3.19 - 162. Measurement inputs of the U03rd> function.
Signal
Description
Time base
3
rd
harmonic voltage (U0)
3
rd
harmonic neutral voltage
5ms
Positive sequence current (I1)
Positive sequence current (I1)
5ms
Pick-up
The function has an inbuilt low-current blocking feature to prevent faulty trips. It is set by the
Low
current blocking I1< set parameter. If this parameter is set above zero (0), the measured positive
sequence current must be above the set limit for the function to trip.
The
Pick-up setting U03h< set setting parameter controls the pick-up of the 100 % stator earth fault
protection function. This defines the minimum allowed measured neutral 3
rd
harmonic voltage before
action from the function. The function constantly calculates the ratio between the
U
set
< and the
measured magnitude. The reset ratio of 103 % is built into the function and is always relative to the
U
set
< value.
Table. 5.3.19 - 163. Pick-up settings.
Name
Description
Range
Step
Default
U
0 3rd
meas
input select
Voltage input must be selected if both U3 and U4 have been set to
"U0" mode.
0: U3 input
1: U4 input
2: Select
-
2:
Select
Uset<
Pick-up setting
1.00…100.00%U
n
0.01%U
n
20%U
n
A
AQ
Q-G215
-G215
Instruction manual
Version: 2.04
243
Содержание AQ-G215
Страница 1: ...AQ G215 Generator protection IED Instruction manual ...
Страница 399: ...Figure 7 4 241 Example block scheme A AQ Q G215 G215 Instruction manual Version 2 04 398 ...
Страница 421: ...Figure 8 14 264 Panel cutout dimensions and device spacing A AQ Q G215 G215 Instruction manual Version 2 04 420 ...
Страница 456: ...10 Ordering information A AQ Q G215 G215 Instruction manual Version 2 04 455 ...