ABB Relion REC670, Applications Manual

Page: 255 / 658

Therefore a tuning parameter CrvSatn is set to compensate for this phenomenon. In the
voltage interval Pickup> up to Pickup> · (1.0 + CrvSatn /100) the used voltage will be:
Pickup> · (1.0 + CrvSatn /100). If the programmable curve is used, this parameter must
be calculated so that:
0
100
CrvSatn
B C
× - >
EQUATION1448 V1 EN-US
(Equation 93)
HystAbsn : Absolute hysteresis set in % of VBase . The setting of this parameter is
highly dependent of the application. If the function is used as control for automatic
switching of reactive compensation devices the hysteresis must be set smaller than the
voltage change after switching of the compensation device.
9.3 Two step residual overvoltage protection ROV2PTOV
(59N)
IP14546-1 v4
9.3.1 Identification
SEMOD54295-2 v6
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Two step residual overvoltage
protection
ROV2PTOV
2(U0>)
IEC15000108 V1 EN-US
59N
9.3.2 Application
M13809-3 v8
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 the measurement of the three phase-to-ground 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
1MRK 511 401-UUS A
Section 9
Voltage protection
Bay control REC670 2.2 ANSI 249
Application manual