Stub Protection Stbptoc; Pole Discordance Protection Ccpdsc; Broken Conductor Check Brcptoc; Voltage-Restrained Time Overcurrent Protection Vrpvoc - ABB REC670 Product Manual

Bay control REC670 2.2
Product version: 2.2.1
The thermal overload protection estimates the internal heat
content of the transformer (temperature) continuously. This
estimation is made by using a thermal model of the
transformer with two time constants, which is based on
current measurement.
Two warning levels are available. This enables actions in the
power system to be done before dangerous temperatures are
reached. If the temperature continues to increase to the trip
value, the protection initiates a trip of the protected
transformer.
The estimated time to trip before operation is presented.
Breaker failure protection CCRBRF
Breaker failure protection (CCRBRF) ensures a fast backup
tripping of the surrounding breakers in case the own breaker
fails to open. CCRBRF can be current-based, contact-based
or an adaptive combination of these two conditions.
A current check with extremely short reset time is used as
check criterion to achieve high security against unwanted
operation.
Contact check criteria can be used where the fault current
through the breaker is small.
CCRBRF can be single- or three-phase initiated to allow use
with single phase tripping applications. For the three-phase
version of CCRBRF the current criteria can be set to operate
only if two out of four for example, two phases or one phase
plus the residual current start. This gives a higher security to
the back-up trip command.
CCRBRF function can be programmed to give a single- or
three-phase re-trip of its own breaker to avoid unnecessary
tripping of surrounding breakers at an incorrect initiation due
to mistakes during testing.

Stub protection STBPTOC

When a power line is taken out of service for maintenance
and the line disconnector is opened in multi-breaker
arrangements the voltage transformers will mostly be outside
on the disconnected part. The primary line distance
protection will thus not be able to operate and must be
blocked.
The stub protection (STBPTOC) covers the zone between the
current transformers and the open disconnector. The three-
phase instantaneous overcurrent function is released from a
normally open, NO (b) auxiliary contact on the line
disconnector.

Pole discordance protection CCPDSC

An open phase can cause negative and zero sequence
currents which cause thermal stress on rotating machines
and can cause unwanted operation of zero sequence or
negative sequence current functions.
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Normally the own breaker is tripped to correct such a
situation. If the situation persists the surrounding breakers
should be tripped to clear the unsymmetrical load situation.
The Pole discordance protection function (CCPDSC) operates
based on information from auxiliary contacts of the circuit
breaker for the three phases with additional criteria from
unsymmetrical phase currents when required.
Directional over/underpower protection GOPPDOP/
GUPPDUP
The directional over-/under-power protection (GOPPDOP/
GUPPDUP) can be used wherever a high/low active, reactive
or apparent power protection or alarming is required. The
functions can alternatively be used to check the direction of
M11550-6 v17
active or reactive power flow in the power system. There are
a number of applications where such functionality is needed.
Some of them are:
• detection of reversed active power flow
• detection of high reactive power flow
Each function has two steps with definite time delay.

Broken conductor check BRCPTOC

The main purpose of the function Broken conductor check
(BRCPTOC) is the detection of broken conductors on
protected power lines and cables (series faults). Detection
can be used to give alarm only or trip the line breaker.

Voltage-restrained time overcurrent protection VRPVOC

Voltage-restrained time overcurrent protection (VRPVOC)
function can be used as generator backup protection against
short-circuits.
The overcurrent protection feature has a settable current level
that can be used either with definite time or inverse time
characteristic. Additionally, it can be voltage controlled/
restrained.
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One undervoltage step with definite time characteristic is also
available within the function in order to provide functionality
for overcurrent protection with undervoltage seal-in.
Capacitor bank protection CBPGAPC
Shunt Capacitor Banks (SCB) are used in a power system to
provide reactive power compensation and power factor
correction. They are as well used as integral parts of Static
Var Compensators (SVC) or Harmonic Filters installations.
Capacitor bank protection (CBPGAPC) function is specially
designed to provide protection and supervision features for
SCBs.
M13269-3 v15 7. Voltage protection
Two-step undervoltage protection UV2PTUV
Undervoltages can occur in the power system during faults or
abnormal conditions. The two-step undervoltage protection
function (UV2PTUV) can be used to open circuit breakers to
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