ABB Relion 650 Series Technical Manual page 256

Section 7
Voltage protection
7.3.7.4 Design
The voltage measuring elements continuously measure the residual voltage. Recursive Fourier
filters filter the input voltage signal. The single input voltage is compared to the set value, and is
also used for the inverse time characteristic integration. The design of Two step residual
overvoltage protection (ROV2PTOV, 59N) is schematically described in
VN
ANSI08000013 V1 EN-US
Figure 127: Schematic design of Two step residual overvoltage protection (ROV2PTOV, 59N)
250
Comparator
Phase 1
VN > Pickup1
PICKUP
Time integrator
TRIP
t1
Phase 1
Comparator
VN > Pickup2
PICKUP
Timer
TRIP
t2
The design of Two step residual overvoltage protection (ROV2PTOV, 59N) is
schematically described in
group signal V3P which shall be connected to output AI3P of the SMAI. If a
connection is made to the 4 input GRPx_N (x is equal to instance number 2 to 12) on
the SMAI, VN is this signal else VN is the vectorial sum of the three inputs GRPx_A
to GRPx_C.
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Pickup
&
Trip
Output
Logic
Step 1
Pickup
&
Trip
OR
Output
Logic
Step 2
OR
ANSI08000013-1-en.vsd
Figure 127. VN is a signal included in the three phase
1MRK 506 326-UUS B
M15331-32 v5
Figure 127.
PU_ST1
TRST1
PU_ST2
TRST2
PICKUP
TRIP
Line distance protection REL650
Technical manual