tReset1
U1>
START
TRIP
t1
IEC10000038-2-en.vsd
IEC10000038 V2 EN-US
Figure 117: Example for Definite Time Delay stage 1 operation
9.2.7.3 Blocking
M15330-20 v8
It is possible to block Two step overvoltage protection OV2PTOV partially or
completely, by binary input signals where:
BLOCK:
blocks all outputs
BLKTR1: blocks all trip outputs of step 1
BLKST1: blocks all start and trip outputs related to step 1
BLKTR2: blocks all trip outputs of step 2
BLKST2: blocks all start and trip outputs related to step 2
9.2.7.4 Design
M15330-34 v8
The voltage measuring elements continuously measure the three phase-to-earth
voltages or the three phase-to-phase voltages. Recursive Fourier filters or true RMS
filters of input voltage signals are used. 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.
Section 9 1MRK 505 394-UEN A
Voltage protection
252 Line differential protection RED650 2.2 IEC
Technical manual
To Next Page
Loading...
