Two Step Residual Overvoltage Protection Rov2Ptov (59N) - ABB REL650 Applications Manual

Section 8
Voltage protection
8.3
8.3.1
8.3.2
8.3.3
262
Two step residual overvoltage protection ROV2PTOV
(59N)
Identification
Function description
Two step residual overvoltage
protection
Application
Two step residual overvoltage protection ROV2PTOV (59N) is primarily used in high
impedance grounded distribution networks, mainly as a backup for the primary ground
fault protection of the feeders and the transformer. To increase the security for different
ground fault related functions, the residual overvoltage signal can be used as a release
signal. The residual voltage can be measured either at the transformer neutral or from a
voltage transformer open delta connection. The residual voltage can also be calculated
internally, based on measurement of the three-phase voltages.
In high impedance grounded systems the residual voltage will increase in case of any fault
connected to ground. Depending on the type of fault and fault resistance the residual
voltage will reach different values. The highest residual voltage, equal to three times the
phase-to-ground voltage, is achieved for a single phase-to-ground fault. The residual
voltage increases approximately to the same level in the whole system and does not
provide any guidance in finding the faulted component. Therefore, ROV2PTOV (59N) is
often used as a backup protection or as a release signal for the feeder ground fault
protection.
Setting guidelines
All the voltage conditions in the system where ROV2PTOV (59N) performs its functions
should be considered. The same also applies to the associated equipment, its voltage and
time characteristic.
There is a very wide application area where general single input or residual overvoltage
functions are used. All voltage related settings are made as a percentage of a settable base
voltage, which can be set to the primary nominal voltage (phase-phase) level of the power
system or the high voltage equipment under consideration.
IEC 61850 IEC 60617
identification identification
ROV2PTOV
3U0>
IEC10000168 V1 EN
1MRK 506 334-UUS A
ANSI/IEEE C37.2
device number
59N
Application manual