Equipment Protection, Such As For Motors And Generators; Disconnected Equipment Detection; Power Supply Quality; Voltage Instability Mitigation - ABB Relion 650 Series Applications Manual

Section 9
Voltage protection
All the voltage conditions in the system where UV2PTUV 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 undervoltage functions are used. All
voltage related settings are made as a percentage of the global settings base voltage
which normally is set to the primary nominal voltage level (phase-to-phase) of the power
system or the high voltage equipment under consideration.
The setting for UV2PTUV is normally not critical, since there must be enough time available for
the main protection to clear short circuits and earth faults.
Some applications and related setting guidelines for the voltage level are described in the
following sections.
9.1.3.1

Equipment protection, such as for motors and generators

The setting must be below the lowest occurring "normal" voltage and above the lowest
acceptable voltage for the equipment.
9.1.3.2

Disconnected equipment detection

The setting must be below the lowest occurring "normal" voltage and above the highest
occurring voltage, caused by inductive or capacitive coupling, when the equipment is
disconnected.
9.1.3.3

Power supply quality

The setting must be below the lowest occurring "normal" voltage and above the lowest
acceptable voltage, due to regulation, good practice or other agreements.
9.1.3.4

Voltage instability mitigation

This setting is very much dependent on the power system characteristics, and thorough
studies have to be made to find the suitable levels.
9.1.3.5

Backup protection for power system faults

The setting must be below the lowest occurring "normal" voltage and above the highest
occurring voltage during the fault conditions under consideration.
9.1.3.6

Settings for Two step undervoltage protection

The following settings can be done for two step undervoltage protection (UV2PTUV).
Common base IED values for primary current (
power (
GlobalBaseSel is used to select a GBASVAL function for reference of base values.
ConnType: Sets whether the measurement shall be phase-to-earth fundamental value, phase-
to-phase fundamental value, phase-to-earth RMS value or phase-to-phase RMS value.
Operation : Off/On .
UV2PTUV measures selectively phase-to-earth voltages, or phase-to-phase voltage chosen by
the setting
150
SBase ) are set in a Global base values for settings function GBASVAL. Setting
ConnType .
© Copyright 2011 ABB Power Grids. All rights reserved
IBase ), primary voltage ( UBase ) and primary
Transformer protection RET650
1MRK 504 124-UEN B
UBase ,
M13851-50 v3
M13851-53 v3
M13851-56 v3
M13851-59 v3
M13851-62 v3
M13851-65 v6
Application manual