ABB Relion 650 Series Technical Manual page 294

Section 10
Control
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 arrangements, SESRSYN (25) function blocks have the capability to make
the necessary voltage selection. The selection of correct voltage is made using auxiliary contacts
of the bus disconnectors.
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.
10.1.7.2 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
The function compares bus and line values with the set values for acceptable frequency, phase
angle and voltage difference:
compensation factor is set due to the use of different voltages on the bus and line, the factor is
deducted from the line voltage before the comparison of the phase angle values.
The frequency on both sides of the circuit breaker is also measured. The frequencies must not
deviate from the rated frequency more than +/-5Hz. The frequency difference between the bus
frequency and the line frequency is measured and may not exceed the set value.
Two sets of settings for frequency difference and phase angle difference are available and used
for the manual closing and autoreclose functions respectively, as required.
The inputs BLOCK and BLKSC are available for total block of the complete Synchronism check
function and block of the Synchronism check function respectively. Input TSTSC will allow testing
of the function where the fulfilled conditions are connected to a separate test output.
The outputs MANSYOK and AUTOSYOK are activated when the actual measured conditions match
the set conditions for the respective output. The output signal can be delayed independently for
MANSYOK and AUTOSYOK conditions.
A number of outputs are available as information about fulfilled checking conditions. VOKSC
shows that the voltages are high, VDIFFSC, FRDIFFA, FRDIFFM, PHDIFFA, PHDIFFM shows when
the voltage difference, frequency difference and phase angle difference conditions are met.
288
OperationSC = Enabled , the measuring will start.
FreqDiffA , FreqDiffM , PhaseDiffA , PhaseDiffM and VDiffSC . If a
© Copyright 2011 ABB Power Grids. All rights reserved
1MRK 506 326-UUS B
M14834-3 v6
Line distance protection REL650
Technical manual