How synchronizer relay works

In parallel operation two different circuits are connected together called synchronized. A mismatch circuit if are synchronized, there will be flushing and other disaster incident.

The function of a synchronizer relay is to control the total synchronization procedure of alternators or different power circuits. We know that for synchronization the voltage, phase angle and frequency must be matched for two power circuits. Synchronizer relay watch over this parameters and when the condition fulfills, commands the close signal to circuit breaker to make to system synchronized.

An industrial synchronizer measures the bus bar and generator voltages and frequencies and compares these, and compares their phase angles. It controls the generator frequency and voltage, until they match the bus bar values.

In order to determine phase accordance between the generator and the bus bar, the synchronizer calculates a phase angle advance based on the circuit breaker closing time and the slip frequency.

When the phase difference is within this tolerance, the synchronizer transmits a closing signal for the generator circuit breaker ñ allowing time for this to close.

                                                      Fig: Connection diagram of a synchronizer