Voltage Protection - ABB REL670 Product Manual

Line distance protection REL670 2.2
Product version: 2.2
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.

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
prepare for system restoration at power outages or as a long-
time delayed back-up to the primary protection.
UV2PTUV has two voltage steps, each with inverse or definite
time delay.
It has a high reset ratio to allow settings close to the system
service voltage.
ABB
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.
Two step residual overvoltage protection ROV2PTOV
Residual voltages may occur in the power system during earth
faults.
Two step residual overvoltage protection (ROV2PTOV) function
calculates the residual voltage from the three-phase voltage
input transformers or measures it from a single voltage input
transformer fed from an open delta or neutral point voltage
transformer.
ROV2PTOV has two voltage steps, each with inverse or definite
time delay.
A reset delay ensures operation for intermittent earth faults.
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 506 372-BEN -
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