ABB 615 Series ANSI, Technical Manual

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Section 7
1MAC050144-MB C
Control functions
520 615 series ANSI
Technical Manual
The Minimum Syn time setting time can be set, if required, to demand the minimum time
within which conditions must be simultaneously fulfilled before the SYNC_OK output is
activated.
The measured voltage, frequency and phase angle difference values between the two sides
of the circuit breaker are available as monitored data values V_DIFF_MEAS,
FR_DIFF_MEAS and PH_DIFF_MEAS. Also, the indications of the conditions that are
not fulfilled and thus preventing the breaker closing permission, are available as monitored
data values V_DIFF_SYNC, PH_DIF_SYNC and FR_DIFF_SYNC. These monitored
data values are updated only when the synchrocheck enabled with the
Synchro check mode
setting and the measured ENERG_STATE is "Both Live".
Continuous mode
The synchrocheck functionality can be selected with the Control mode setting. The
"Continuous" mode can be used for two different operating conditions, the most typical of
which is where both sides of the circuit breaker to be closed are live. The synchronism is
always checked before the circuit breaker is given the permission to close. The other
situation is where one or both sides of the circuit breaker to be closed are dead and,
consequently, the frequency and phase difference cannot be measured. In this case, the
function checks the energizing direction. The user is able to define the voltage range within
which the measured voltage is determined to be "live" or "dead".
The continuous control mode is selected with the Control mode setting. In the continuous
control mode, the synchrocheck is continuously checking the synchronism. When the
synchronism conditions or the energizing check conditions are fulfilled, the SYNC_OK
output is activated and it remains activated as long as the conditions remain fulfilled. The
command input is ignored in the continuous control mode. The mode is used for situations
where the synchrocheck only gives the permission to the control block that executes the
CB closing.
Figure 283: A simplified block diagram of the synchrocheck function in the
continuous mode operation
Command mode
If Control mode is set to "Command", the purpose of the synchrocheck functionality in the
command mode is to find the instant when the voltages on both sides of the circuit breaker
are in synchronism. The conditions for synchronism are met when the voltages on both
25 52
I
Closing
permission
Closing
command