METHOD OF PARALLEL MAKING OF INDUCTION GENERATOR IN SYSTEM

PURPOSE:To carry out parallel making operation with scarce voltage impact without inserting a DC reactor into a main circuit, by operating a wound-rotor induction generator as a synchronous generator only when it is thrown into a system. CONSTITUTION:Rotary shaft of a generator 1 is driven through a prime mover, then it is regulated to rated speed thereafter a switch is made. An AC switch 8 is thrown in at this time, and the secondary of the generator 1 is applied with DC voltage from a rectifier 7 and subjected to DC excitation. When amplitude, frequency and phase at the primary of the generator satisfy synchronous parallel making conditions of system voltage, a making command is provided to a circuit breaker 3 to make a switch 5 and open the switch 6 after parallel making operation. Consequently, terminal of secondary winding is shortcircuited through a resistor 4 having required resistance, and thereby the generator 1 operates as an induction generator while being linked with the system.