ABB Relion 670 Series Technical Reference Manual page 548

Section 8
Voltage protection
8.5
8.5.1
8.5.2
542
Function
Curve type
Minimum time delay for inverse
function
Maximum time delay for inverse
function
Alarm time delay
Voltage differential protection VDCPTOV (60)
Function description
Voltage differential protection
Introduction
A voltage differential monitoring function is available. It compares the voltages from
two three phase sets of voltage transformers and has one sensitive alarm step and one
trip step.
Principle of operation
The Voltage differential protection function VDCPTOV (60) is based on comparison
of the magnitudes of the two voltages connected in each phase. Possible differences
between the ratios of the two Voltage/Capacitive voltage transformers can be
compensated for with a ratio correction factors RF_X. The voltage difference is
evaluated and if it exceeds the alarm level VDAlarm or trip level VDTrip signals for
alarm (ALARM output) or trip (TRIP output) is given after definite time delay tAlarm
respectively tTrip. The two three phase voltage supplies are also supervised with
undervoltage settings V1Low and V2Low. The outputs for loss of voltage V1LOW resp
V2LOW will be activated. The V1 voltage is supervised for loss of individual phases
whereas the V2 voltage is supervised for loss of all three phases.
Loss of all U1or all U2 voltages will block the differential measurement. This blocking
can be switched off with setting BlkDiffAtULow = No.
Range or value
IEEE or customer defined
×
(0.18 TD )
=
IEEE t :
-
2
( M 1)
(Equation 146)
EQUATION1645 V1 EN
where M = (E/f)/(Vn/fn)
(0.000–60.000) s
(0.00–9000.00) s
(0.00–9000.00)
IEC 61850 IEC 60617
identification identification
VDCPTOV
1MRK505222-UUS C
Accuracy
± 5% + 40 ms
± 0.5% ± 10 ms
± 0.5% ± 10 ms
± 0.5% ± 10 ms
ANSI/IEEE C37.2
device number
- 60
Technical reference manual