Blocking; Design - ABB Relion 670 Series Technical Reference Manual

1MRK 505 208-UEN B
7.2.2.3
7.2.2.4
Technical reference manual
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START
TRIP
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IEC10000038 V1 EN
Figure 117: Example for Definite Time Delay stage operation

Blocking

It is possible to block Two step overvoltage protection OV2PTOV partially or
completely, by binary input signals where:
BLOCK:
BLKTR1:
BLKST1:
BLKTR2:
BLKST2:

Design

The voltage measuring elements continuously measure the three phase-to-earth
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 START condition. The design of Two step overvoltage protection
(OV2PTOV) is schematically described in figure 118.
blocks all outputs
blocks all trip outputs of step 1
blocks all start and trip outputs related to step 1
blocks all trip outputs of step 2
blocks all start and trip outputs related to step 2
Section 7
Voltage protection
IEC10000038-1-en.vsd
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