ABB RELION 670 Series Applications Manual page 210

Section 8
Voltage protection
8.2 Two step overvoltage protection OV2PTOV (59)
8.2.1 Identification
Function description
Two step overvoltage protection
8.2.2 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 expectancy. In many
cases, it is a useful function in circuits for local or remote automation processes in the power
system.
204
IEC 61850 IEC 60617
identification identification
OV2PTOV
3U>
SYMBOL-C-2U-SMALLER-THAN V2 EN-US
1MRK 505 337-UUS A
IP14545-1 v3
M17002-1 v7
ANSI/IEEE C37.2
device number
59
M13799-3 v8
Application manual