Voltage Protection; Secondary System Supervision - ABB Relion 650 Series Product Manual

Busbar protection REB650
Version 1.1 ANSI
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 unintentional
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.
OV2PTOV (59) has two voltage steps, where step 1 can be
set as inverse or definite time delayed. Step 2 is always
definite time delayed.
OV2PTOV (59) has an extremely high reset ratio to allow
settings close to system service voltage.
Two step residual overvoltage protection ROV2PTOV
(59N)
Residual voltages may occur in the power system during
ground faults.
Two step residual overvoltage protection ROV2PTOV (59N)
function calculates the residual voltage from the three-
phase voltage input transformers or measures it from a
single voltage input transformer fed from a broken delta
or neutral point voltage transformer.
ROV2PTOV (59N) has two voltage steps, where step 1 can
be set as inverse or definite time delayed. Step 2 is always
definite time delayed.
ABB Power Grids

7. Secondary system supervision

Fuse failure supervision SDDRFUF
The aim of the fuse failure supervision function
(SDDRFUF) is to block voltage measuring functions at
failures in the secondary circuits between the voltage
transformer and the IED in order to avoid unwanted
operations that otherwise might occur.
The fuse failure supervision function basically has three
different algorithms, negative sequence and zero
sequence based algorithms and an additional delta
voltage and delta current algorithm.
M13789-3 v7
The negative sequence detection algorithm is
recommended for IEDs used in isolated or high-impedance
grounded networks. It is based on the negative-sequence
measuring quantities, a high value of voltage without the
presence of the negative-sequence current 3I
The zero sequence detection algorithm is recommended
for IEDs used in directly or low impedance grounded
networks. It is based on the zero sequence measuring
quantities, a high value of voltage 3V
presence of the residual current 3I
M13798-3 v7
A criterion based on delta current and delta voltage
measurements can be added to the fuse failure
supervision function in order to detect a three phase fuse
failure, which in practice is more associated with voltage
transformer switching during station operations.
For better adaptation to system requirements, an
operation mode setting has been introduced which makes
it possible to select the operating conditions for negative
sequence and zero sequence based function. The selection
of different operation modes makes it possible to choose
different interaction possibilities between the negative
sequence and zero sequence based algorithm.
M13808-3 v8
Breaker close/trip circuit monitoring TCSSCBR
The trip circuit monitoring function TCSSCBR is designed
for supervision of control circuits. A fault in a control
circuit is detected by using a dedicated output contact
that contains the monitoring functionality.
The function picks up and trips when TCSSCBR detects a
trip circuit failure. The trip time characteristic for the
function is of definite time (DT) type. The function trips
after a predefined operating time and resets when the
fault disappears.
© Copyright 2011 ABB Power Grids. All rights reserved
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