| 摘要 |
PURPOSE:To decrease a stopping time and realize an effective stopping control in a synchronous machine by dynamic braking an induction motor linked with the synchronous machine by means of an exciting system of the synchronous machine and then by dynamic braking the synchronous maching using a start-up adjusting resistor of the induction motor. CONSTITUTION:During a stopping control time, a braker 13 is opened by a stop command to disconnect a synchronous machine 1 from a system, and at the same time a breaker 12 is opened to stop supply of a field current from a thyristor exciting unit 9. Further, a switching connector 26 is turned to a firing angle control circuit 27a side, a breaker 28 is switched on, and an induction motor 2 is dynamic braked via the thyristor exciting unit 9. Through this procedure, the revolution speed of the synchronous machine 1 is reduced to 30-50% of the rated value. Afterwards, opening the breaker 28, switching on a breaker 30, turning the switching connector 26 to a firing angle control circuit 27b side, controlling the firing of the thyristor exciting unit 9 and also switching on the breaker 12, to supply a field current, the synchronous machine 1 is dynamic braked to complete stop. |
