Identification - ABB RELION RET670 Applications Manual

1MRK 504 163-UUS A
10.2.1
10.2.2
Transformer protection RET670 2.2 ANSI
Application manual

Identification

Function description
Two step overvoltage protection
Application
Two step overvoltage protection OV2PTOV (59) is applicable in all situations, where
reliable detection of high voltage is necessary. OV2PTOV (59) is used for supervision
and detection of abnormal conditions, which, in combination with other protection
functions, increase the security of a complete protection system.
High overvoltage conditions are caused by abnormal situations in the power system.
OV2PTOV (59) is applied to power system elements, such as generators, transformers,
motors and power lines in order to detect high voltage conditions. OV2PTOV (59) is
used in combination with low current signals, to identify a transmission line, open in
the remote end. In addition to that, OV2PTOV (59) is also used to initiate voltage
correction measures, like insertion of shunt reactors, to compensate for low load, and
thereby decreasing the voltage. The function has a high measuring accuracy and
hysteresis setting to allow applications to control reactive load.
OV2PTOV (59) is used to disconnect apparatuses, like electric motors, which will be
damaged when subject to service under high voltage conditions. It deals with high
voltage conditions at power system frequency, which can be caused by:
1. Different kinds of faults, where a too high voltage appears in a certain power
system, like metallic connection to a higher voltage level (broken conductor
falling down to a crossing overhead line, transformer flash over fault from the high
voltage winding to the low voltage winding and so on).
2. Malfunctioning of a voltage regulator or wrong settings under manual control
(symmetrical voltage decrease).
3. Low load compared to the reactive power generation (symmetrical voltage
decrease).
4. Ground-faults in high impedance grounded systems causes, beside the high
voltage in the neutral, high voltages in the two non-faulted phases, (unsymmetrical
voltage increase).
OV2PTOV (59) prevents sensitive equipment from running under conditions that could
cause their overheating or stress of insulation material, and, thus, shorten their life time
IEC 61850 IEC 60617 identification
identification
OV2PTOV
3U>
SYMBOL-C-2U-SMALLER-THAN V2 EN-US
Section 10
Voltage protection
M17002-1 v8
ANSI/IEEE C37.2
device number
59
M13799-3 v9
617