Generator & Bus Auto Synchroniser System

Successfully synchronizing a generator requires that three parameters be within close acceptance criteria. 

➤ Slip (frequency difference) in acceptance band

➤ Voltage difference in acceptance band 

➤ Angle difference near zero

The heart of an autosynchronizer is the slip-compensated advanced angle close function that compensates for the breaker mechanism delay and energizes the synchronizing breaker close coil at the precise instant to cause the main contacts to make contact at zero  degrees angle difference. 

Additionally, the A25A has features to control the generator to match frequency and voltage by pulsing the reference points of the governor and voltage regulator controls, respectively, to bring these parameters into the synchronizing acceptance bands.

SEL Autosynchronization System Capabilities (base system): 

    • Frequency raise/lower controls
    • Voltage raise/lower controls
    • Generator Frequency Greater Than Bus Frequency (GF > BF)  Antimotoring
    • Local monitoring
    • Dead-bus close