ABB Relion 670 Series Applications Manual page 197

1MRK 511 401-UUS F
8.11.1 Identification
Function description
Pole discrepancy protection
8.11.2 Application
There is a risk that a circuit breaker will get discrepancy between the poles at circuit breaker
operation: closing or opening. One pole can be open and the other two closed, or two poles can be
open and one closed. Pole discrepancy of a circuit breaker will cause unsymmetrical currents in the
power system. The consequence of this can be:
• Negative sequence currents that will give stress on rotating machines
• Zero sequence currents that might give unwanted operation of sensitive ground-fault
protections in the power system.
It is therefore important to detect situations with pole discrepancy of circuit breakers. When this
is detected the breaker should be tripped directly.
Pole discordance protection CCPDSC (52PD) will detect situation with deviating positions of the
poles of the protected circuit breaker. The protection has two different options to make this
detection:
• By connecting the auxiliary contacts in the circuit breaker so that logic is created, a signal can
be sent to the protection, indicating pole discrepancy. This logic can also be realized within
the protection itself, by using opened and close signals for each circuit breaker pole,
connected to the protection.
• Each phase current through the circuit breaker is measured. If the difference between the
phase currents is larger than a
protection will operate.
8.11.3 Setting guidelines
The parameters for the Pole discordance protection CCPDSC (52PD) are set via the local HMI or
PCM600.
The following settings can be done for the pole discrepancy protection.
GlobalBaseSel : Selects the global base value group used by the function to define IBase , VBase and
SBase . Note that this function will only use IBase value.
Operation : Disabled or Enabled
tTrip : Time delay of the operation.
Bay control REC670
Application manual
IEC 61850
identification
CCPDSC
CurrUnsymPU this is an indication of pole discrepancy, and the
© Copyright 2017 ABB. All rights reserved
IEC 60617 ANSI/IEEE C37.2
identification device number
52PD
PD
SYMBOL-S V1 EN-US
Section 8
Current protection
M14888-1 v4
M13270-3 v6
M13274-3 v8
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