Loss Of Voltage Check Lovptuv (27) - ABB REL650 Applications Manual

1MRK 506 334-UUS A
8.4
8.4.1
8.4.2
8.4.3
8.4.4
Application manual

Loss of voltage check LOVPTUV (27)

Identification
Function description
Loss of voltage check
Application
The trip of the circuit breaker at a prolonged loss of voltage at all the three phases is
normally used in automatic restoration systems to facilitate the system restoration after a
major blackout. Loss of voltage check (LOVPTUV, 27) generates a TRIP signal only if
the voltage in all the three phases is low for more than the set time. If the trip to the circuit
breaker is not required, LOVPTUV (27) is used for signallization only through an output
contact or through the event recording function.
Setting guidelines
Loss of voltage check (LOVPTUV, 27) is in principle independent of the protection
functions. It requires to be set to open the circuit breaker in order to allow a simple system
restoration following a main voltage loss of a big part of the network and only when the
voltage is lost with breakers still closed.
GlobalBaseSel: Selects the global base value group used by the function to define (IBase),
(VBase) and (SBase).
All settings are in primary values or per unit. Set operate level per phase to typically 70%
of the global parameter VBase level. Set the time delay tTrip=5-20 seconds.
Advanced users settings
For advanced users the following parameters need also to be set. Set the length of the trip
pulse to typical tPulse=0.15 sec. Set the blocking time tBlock to block Loss of voltage
check (LOVPTUV, 27), if some but not all voltage are low, to typical 5.0 seconds and set
the time delay for enabling the function after restoration tRestore to 3 - 40 seconds.
IEC 61850 IEC 60617
identification identification
LOVPTUV -
Section 8
Voltage protection
ANSI/IEEE C37.2
device number
27
267