ABB Relion 670 series - Page 616

Time
V
Normal voltage
Pickup1
Pickup2
IntBlkStVal1
IntBlkStVal2
Disconnection
tBlkUV1 <
t1,t1Min
tBlkUV2 <
t2,t2Min
Block step 1
Block step 2
en05000466_ansi.vsd
ANSI05000466 V1 EN-US
Figure 329: Blocking function
9.1.7.4 Design
M15326-35 v7
The voltage measuring elements continuously measure the three phase-to-neutral voltages or the
three phase-to-phase voltages. Recursive fourier filters or true RMS filters of input voltage signals
are used. The voltages are individually compared to the set value, and the lowest 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 and 3 out of 3 criteria to fulfill the PICKUP condition. The design of Two step undervoltage
protection UV2PTUV (27) is schematically shown in
Figure 330.
Section 9 1MRK 502 066-UUS B
Voltage protection
610
Technical manual