PURPOSE: To lower lagging reactive power at the time of starting, and to reduce the voltage drop of a system by connecting a capacitor for starting in parallel with an autotransformer.

CONSTITUTION: When large-sized synchronous motors 1∼4 are started, circuit breakers 9, 14, 15 are turned ON first, and an autotransformer 13 for a Kondorfer starter is connected to the synchronous motor 1. When the synchronous motor 1 is started, the circuit breaker 9 is interrupted while a circuit breaker 5 is turned ON, and the synchronous motor 1 is charged to a system. Likewise, the synchronous motors 2∼4 are started. A capacitor 16 for starting is connected in parallel with the autotransformer 13. Accordingly, the lagging reactive power section of starting power due to the autotransformer can be lowered, and a voltage drop can be reduced.