Setting Guidelines; Disconnected Equipment Detection; Power Supply Quality; Voltage Instability Mitigation - ABB RER670 Applications Manual

Section 9
Voltage protection
9.1.3
9.1.3.1
9.1.3.2
9.1.3.3
9.1.3.4
9.1.3.5
196
it is a useful function in circuits for local or remote automation processes in the
power system.

Setting guidelines

All the voltage conditions in the system where U2RWPTUV performs its functions
should be considered. The same also applies to the associated equipment, its
voltage and time characteristic.
There are wide applications where general undervoltage functions are used. All
voltage related settings are made as a percentage of the global base value UBase
and base current IBase, which normally is set to the primary rated voltage level
(phase-to-phase) of the power system or the high voltage equipment under
consideration.
The setting for U2RWPTUV 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.

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.

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.

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.

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.

Settings for two step undervoltage protection

Parameters for U2RWPTUV application function are set via local HMI or
Protection and Control Manager PCM600.
1MRK 506 375-UEN A
M13851-65 v14
Railway application RER670 2.2 IEC
Application manual
M13851-3 v9
M13851-53 v3
M13851-56 v3
M13851-59 v3
M13851-62 v3