ABB RELION 620 Series Technical Manual page 645

1MRS757644 F
4.5.2.7
4.5.2.8
Table 586: PHAPTOV Group settings (Basic)
Parameter Values (Range)
Start value
Time multiplier
Operate delay time
Operating curve type
620 series
Technical Manual
The power frequency overvoltage may occur in the network due to contingencies such
as:
• Defective operation of the automatic voltage regulator when the generator is in
isolated operation.
• Operation under manual control with the voltage regulator out of service. A
sudden variation of load, in particular the reactive power component, gives rise to
a substantial change in voltage because of the large voltage regulation inherent in
a typical alternator.
• Sudden loss of load due to the tripping of outgoing feeders, leaving the generator
isolated or feeding a very small load, can cause a sudden rise in the terminal
voltage due to the trapped field flux and overspeed.
If a load sensitive to overvoltage remains connected, it leads to equipment damage.
It is essential to provide power frequency overvoltage protection, in the form of time
delayed element, either IDMT or DT to prevent equipment damage.
Signals
Table 584: PHAPTOV Input signals
Name
U_A_AB
BLOCK
Table 585: PHAPTOV Output signals
Name
OPERATE
START
Settings
Unit
0.05...1.60 xUn
0.05...15.00
40...300000 ms
5=ANSI Def. Time
15=IEC Def. Time
17=Inv. Curve A
18=Inv. Curve B
19=Inv. Curve C
20=Programmable
Type Default Description
SIGNAL 0 Phase-to-earth voltage A or phase-to-phase
voltage AB
BOOLEAN 0=False Block signal for activating the blocking mode
Type Description
BOOLEAN Operate
BOOLEAN Start
Step Default
0.01 1.10
0.01 1.00
10 40
15=IEC Def. Time
Section 4
Protection functions
Description
Start value
Time multiplier in IEC/ANSI IDMT curves
Operate delay time
Selection of time delay curve type
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