| 摘要 |
PURPOSE:To cancel the offset of a current sensor connected with the irregular output torque of a current minor loop by providing polarity inverting means having a polarity inverter and a limiter between a speed error amplifier and a current minor loop. CONSTITUTION:Polarity inverting means 19 having a polarity inverter 19a and a limiter 19b is connected between a speed error amplifier 1 and a current error amplifier 2. An addition signal of a feedback signal IM and a current command value from the error amplifier 1 is input to the means 19, the output of the inverter 19a is limited at the maximum value by the limiter 19b, and input as a command signal to the current minor loop after the amplifier 1. The minor loop has the amplifier 2, a PWM circuit 3, a current commutation circuit 4, a drive circuit 5, a power switch 6, a current sensor 11 and a detecting current selector 7. |
