ABB Relion 670 Series Technical Reference Manual page 518

Section 8
Voltage protection
8.2.2.3
8.2.2.4
512
Pickup1
PICKUP
TRIP
tReset1
t1
ANSI10000038 V2 EN
Figure 262: Example for Definite Time Delay stage operation
Blocking
It is possible to block Two step overvoltage protection OV2PTOV, (59) partially or
completely, by binary input signals where:
BLOCK:
BLKTR1:
BLK1:
BLKTR2:
BLK2:
Design
The voltage measuring elements continuously measure the three phase-to-ground
voltages or the three phase-to-phase voltages. Recursive Fourier filters filter the input
voltage signals. The phase voltages are individually compared to the set value, and the
highest voltage is used for the inverse time characteristic integration. A special logic is
included to achieve the 1 out of 3, 2 out of 3 or 3 out of 3 criteria to fulfill the PICKUP
condition. The design of Two step overvoltage protection (OV2PTOV, 59) is
schematically described in figure 263.
blocks all outputs
blocks all trip outputs of step 1
blocks all pickup and trip outputs related to step 1
blocks all trip outputs of step 2
blocks all pickup and trip outputs related to step 2
1MRK505222-UUS C
ANSI10000038-2-en.vsd
Technical reference manual