Operation Principle - ABB REG650 Technical Manual

1MRK 502 043-UUS B
12.1.7
12.1.7.1
12.1.7.2
Technical Manual

Operation principle

Basic functionality
The synchronism check function measures the conditions across the circuit breaker and
compares them to set limits. The output is only given when all measured quantities are
simultaneously within their set limits.
The energizing check function measures the bus and line voltages and compares them
to both high and low threshold detectors. The output is given only when the actual
measured quantities match the set conditions.
The synchronizing function measures the conditions across the circuit breaker, and also
determines the angle change occurring during the closing delay of the circuit breaker,
from the measured slip frequency. The output is given only when all measured
conditions are simultaneously within their set limits. The issue of the output is timed to
give closure at the optimal time including the time for the circuit breaker and the
closing circuit.
For single circuit breaker double bus and breaker-and-a-half circuit breaker
arrangements, the SESRSYN (25) function blocks have the capability to make the
necessary voltage selection. For single circuit breaker double bus arrangements,
selection of the correct voltage is made using auxiliary contacts of the bus
disconnectors. For breaker-and-a-half circuit breaker arrangements, correct voltage
selection is made using auxiliary contacts of the bus/line disconnectors as well as the
circuit breakers.
The internal logic for each function block as well as, the input and outputs, and the
settings with default setting and setting ranges is described in this document. For
application related information, please refer to the application manual.
Synchronism check
The voltage difference, frequency difference and phase angle difference values are
measured in the IED centrally and are available for the synchronism check function for
evaluation. If the bus voltage is connected as phase-phase and the line voltage as phase-
neutral (or the opposite), this need to be compensated. This is done with a setting,
which scales up the line voltage to a level equal to the bus voltage.
When the function is set to OperationSC = Enabled, the measuring will start.
The function will compare the bus and line voltage values with internally preset values
that are set to be 80% of the set value of GlbBaseSelBus and GlbBaseSelLine.
Section 12
Control
323