overcurrent function is released from a normally
open, 89b auxiliary contact on the line disconnector.
Pole discordance protection CCRPLD (52PD)
Circuit breakers and disconnectors can end up with
their phases in different positions (close-open), due
to electrical or mechanical failures. 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 affected breaker is tripped to correct
such a situation. If the situation warrants the
surrounding breakers should be tripped to clear the
unsymmetrical load situation.
The pole discrepancy function operates based on
information from the circuit breaker logic with
additional criteria from unsymmetrical phase
currents when required.
Broken conductor check BRCPTOC (46)
Conventional protection functions can not detect
the broken conductor condition. Broken conductor
check (BRCPTOC, 46) 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 (32/37)
The directional over-/under-power protection
GOPPDOP (32)/GUPPDUP (37) 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 (46)
Negative sequence based overcurrent function
(DNSPTOC, 46) may be used in power line
applications where the reverse zero sequence
source is weak or open, the forward source
impedance is strong and it is desired to detect
forward ground faults.
Additionally, it is applied in applications on 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 forward,
reverse or non-directional independently for each
step.
DNSPTOC (46) protects against all unbalanced
faults including phase-to-phase faults. The
minimum pickup current of the function must be set
to above the normal system unbalance level in order
to avoid unwanted tripping.
6. Voltage protection
Two step undervoltage protection UV2PTUV (27)
Undervoltages can occur in the power system
during faults or abnormal conditions. Two step
undervoltage protection (UV2PTUV, 27) 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 (27) 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 (59)
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.
Two step overvoltage protection (OV2PTOV, 59)
function can be used to detect open line ends,
normally then combined with a directional reactive
over-power function to supervise the system
Bay control REC650 ANSI
1MRK 511 265-BUS B
Product version: 1.2
ABB 23
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