| 摘要 |
PURPOSE:To stably start and accelerate a synchronous motor by accelerating the motor during turning under a separate frequency control in a low speed rotating range and controlling the rotating speed by using an electric position detector in the speed range higher than that. CONSTITUTION:When a synchronous motor 11 starts being energized as a thyristor motor, an inverter 17-3 starts being energized by a frequency equal to the rotating speed of the motor 11 stored in a holding circuit 21. The output frequency of the inverter 17-3 is not abruptly varied by the operations of the holding circuit 21 and an acceleration limiter 23. Thus, the motor 11 can be stably started and accelerated by following up the rise of the oscillating pulse of an oscillator 20-3. The input frequency of the motor 11 is controlled by the automatic control using an electric position detector 19-1 by the speed of approx. 10-5% of the rated speed. |
