| 摘要 |
PURPOSE:To reduce pulsating torque at starting by connecting a thyristor in parallel with the rotary field coil of a synchronous motor. CONSTITUTION:When the positive half cycle of the induction field current generated in a rotary field coil 2 at the time of starting a synchronous motor appears at a terminal J, a firing signal is supplied to a thyristor 8 through a transformer 7, a diode 10, and a Zener diode 9 and the induction field current is short-circuited through the thyristor 8. When the positive half cycle appears at a terminal K, the induction field current is short-circuited through a rotary silicon rectifier 4. As this method eliminates most of the DC portions of the induction field current at the time of starting, the occurrence of pulsating torque can be reduced. |
