Function Range or value Accuracy
Curve type IEEE or customer defined
2
(0.18 )
:
( 1)
×
=
-
TD
IEEE t
M
EQUATION1645 V1 EN (Equation 146)
where M = (E/f)/(Vn/fn)
± 5% + 40 ms
Minimum time delay for inverse
function
(0.000–60.000) s ± 0.5% ± 10 ms
Maximum time delay for inverse
function
(0.00–9000.00) s ± 0.5% ± 10 ms
Alarm time delay (0.00–9000.00) ± 0.5% ± 10 ms
8.5 Voltage differential protection VDCPTOV (60)
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Voltage differential protection VDCPTOV - 60
8.5.1 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.
8.5.2 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.
Section 8 1MRK505222-UUS C
Voltage protection
542
Technical reference manual
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