ABB Relion 670 Series Applications Manual page 269

1MRK 505 370-UUS Rev. K
Section 12
12.1 Synchronism check, energizing check, and synchronizing
SESRSYN (25)
12.1.1 Identification
Function description
Synchrocheck, energizing check, and
synchronizing
12.1.2 Application
12.1.2.1 Synchronizing
To allow closing of breakers between asynchronous networks, a synchronizing feature is provided. The
breaker close command is issued at the optimum time when conditions across the breaker are satisfied
in order to avoid stress on the network and its components.
The systems are defined as asynchronous when the frequency difference between bus and line is larger
than an adjustable parameter. If the frequency difference is less than this threshold value the system is
defined to have a parallel circuit and the synchronism check function is used.
The synchronizing function measures the difference between the V-Line and the V-Bus. It operates and
enables a closing command to the circuit breaker when the calculated closing angle is equal to the
measured phase angle and the following conditions are simultaneously fulfilled:
• The voltages V-Line and V-Bus are higher than the set values for VHighBusSynch and
VHighLineSynch of the respective base voltages GblBaseSelBus and GblBaseSelLine.
• The difference in the voltage is smaller than the set value of VDiffSynch.
• The difference in frequency is less than the set value of FreqDiffMax and larger than the set value of
FreqDiffMin. If the frequency is less than FreqDiffMin the synchronism check is used and the value
of FreqDiffMin must thus be identical to the value FreqDiffM resp FreqDiffA for synchronism check
function. The bus and line frequencies must also be within a range of ±5 Hz from the rated
frequency. When the synchronizing option is included also for autoreclose there is no reason to have
different frequency setting for the manual and automatic reclosing and the frequency difference
values for synchronism check should be kept low.
• The frequency rate of change is less than set value for both V-Bus and V-Line.
• The difference in the phase angle is smaller than the set value of CloseAngleMax.
• The closing angle is decided by the calculation of slip frequency and required pre-closing time.
The synchronizing function compensates for the measured slip frequency as well as the circuit breaker
closing delay. The phase angle advance is calculated continuously. The calculation of the operation pulse
Busbar protection REB670
Application manual
Control
IEC 61850
identification
SESRSYN
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IEC 60617 ANSI/IEEE C37.2
identification device number
25
sc/vc
SYMBOL-M V1 EN-US
Section 12
Control
IP14558-1 v4
M14889-1 v4
IP15111-1 v1
SEMOD171992-5 v10
263