| 摘要 |
PURPOSE:To avoid runaway of a motor during service interruption, by a method wherein at the service interruption, brake is actively applied utilizing discharge current of a smoothing capacitor in a rectifier circuit, and stop of the rotation is detected, and then excitation drive current is stopped. CONSTITUTION:During service interruption, power supply to a motor control circuit 1 is changed from DC power source to a battery means 13. A speed command circuit 4 receives service interruption signal from a service interruption detecting circuit 3, and supplies zero speed command signal to a motor drive control circuit 7. A motor excitation drive circuit 9, based on the motor drive control signal, supplies excitation drive current so that rotation of the motor is made zero. Then power supply from AC power source 14 is also interrupted due to the service interruption, but the motor 10 is controlled utilizing discharge current of a smoothing capacitor 17 in a rectifier circuit 15. |
