Voltage Protection - ABB REC650 Product Manual

Bay control REC650
Product version: 1.1
The pole discordance function operates based
on information from the circuit breaker logic
with additional criteria from unsymmetrical
phase currents when required.
Broken conductor check BRCPTOC
Conventional protection functions can not
detect the broken conductor condition.
Broken conductor check (BRCPTOC)
function, consisting of continuous current
unsymmetrical check on the line where the
IED is connected will give alarm or trip at
detecting broken conductors.
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. Reset times for both steps can be
set as well.
Negative sequence based
overcurrent function DNSPTOC
Negative sequence based overcurrent
function (DNSPTOC) is typically used as
sensitive earth-fault protection of power
lines, where incorrect zero sequence
polarization may result from mutual
induction between two or more parallel lines.
Additionally, it is applied in applications on
underground cables, where zero sequence
impedance depends on the fault current
return paths, but the cable negative sequence
impedance is practically constant.
The directional function is current and
voltage polarized. The function can be set to
22
1MRK 511 249-BEN -
Issued: February 2011
forward, reverse or non-directional
independently for each step.
DNSPTOC protects against all unbalanced
faults including phase-to-phase faults. The
minimum start current of the function must
be set to above the normal system unbalance
level in order to avoid unintentional
functioning.

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, where step
1 is settable as inverse or definite time
delayed. Step 2 is always definite time delayed.
Two step overvoltage protection
OV2PTOV
Overvoltages may occur in the power system
during abnormal conditions such as sudden
power loss, tap changer regulating failures,
open line ends on long lines etc.
OV2PTOV has two voltage steps, where step
1 can be set as inverse or definite time
delayed. Step 2 is always definite time delayed.
OV2PTOV has an extremely 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
ABB