Voltage Protection; Pole Discordance Protection Ccpdsc; Broken Conductor Check Brcptoc; Voltage Differential Protection Vdcptov - ABB RED670 Product Manual

Line differential protection RED670 2.1 IEC
Product version: 2.1
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.
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
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.
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.
ABB

6. Voltage protection

Two step undervoltage protection UV2PTUV
Undervoltages can occur in the power system during faults or
abnormal conditions. Two step undervoltage protection
(UV2PTUV) function can be used to open circuit breakers to
prepare for system restoration at power outages or as long-
time delayed back-up to primary protection.
UV2PTUV has two voltage steps, each with inverse or definite
time delay.
UV2PTUV has a high reset ratio to allow settings close to
system service voltage.
Two step overvoltage protection OV2PTOV
Overvoltages may occur in the power system during abnormal
conditions such as sudden power loss, tap changer regulating
failures, and open line ends on long lines.
Two step overvoltage protection (OV2PTOV) function can be
used to detect open line ends, normally then combined with a
directional reactive over-power function to supervise the
system voltage. When triggered, the function will cause an
alarm, switch in reactors, or switch out capacitor banks.
OV2PTOV has two voltage steps, each of them with inverse or
definite time delayed.
OV2PTOV has a high reset ratio to allow settings close to
system service voltage.
Overexcitation protection OEXPVPH
When the laminated core of a power transformer or generator is
subjected to a magnetic flux density beyond its design limits,
stray flux will flow into non-laminated components that are not
designed to carry flux. This will cause eddy currents to flow.
These eddy currents can cause excessive heating and severe
damage to insulation and adjacent parts in a relatively short
time. The function has settable inverse operating curves and
independent alarm stages.

Voltage differential protection VDCPTOV

A voltage differential monitoring function is available. It
compares the voltages from two three phase sets of voltage
transformers and has one sensitive alarm step and one trip
step.
Loss of voltage check LOVPTUV
Loss of voltage check LOVPTUV is suitable for use in networks
with an automatic system restoration function. LOVPTUV
issues a three-pole trip command to the circuit breaker, if all
three phase voltages fall below the set value for a time longer
than the set time and the circuit breaker remains closed.
The operation of LOVPTUV is supervised by the fuse failure
supervision FUFSPVC.
1MRK 505 346-BEN -
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