Automatic Synchronizer

Synchronizing meaning the frequency, voltage, phase angle and sequence of phase between unit generator and line grid are same.

These happen while unit start-up and the turbine already 3000 RPM (frequency grid 50Hz) so that we are ready to synchronize generator to grid by close the DS (disconnecting switch between generators to line grid) and FCB (field circuit breaker for created excitation current).


After the FCB close, the generator can create the voltage which the value around 22.8kV and it adjusted through AVR (automatic voltage regulator) for created match deviation voltage between generator and line grid because line grid voltage also not stable too caused by load grid. The function of Thyristor os adjusted current and rectified the excitation current. After synchronize, the AVR also can maintain the voltage or can auto adjusted when the load up and down.

These explanations above are preparation for synchronizing. After everything is ok, we initiate to synchronize, normally sequence of phase (R-S-T) and phases angle match. The task of synchron-scoop (automatic synchronizer) to adjusted the deviation of voltage and frequency.


The voltage is controlled by AVR and the frequency is controlled by turbine control valve via electro hydraulic control system. If all is match reading from each VT (voltage transformer), automatic synchronizer will send the signal to close generator circuit breaker (GMCB).

Information about Theory of Generator, please visit visit http://idpowerstation.blogspot.com/2011/11/generator-theory.html

Information abaout Generator Auxilliary System, please visit http://idpowerstation.blogspot.com/2009/02/generator-auxiliary-system.html