| 摘要 |
PURPOSE:To enable overspeed and overvoltage to be prevented from being generated without neglecting a current rate value, by lowering the speed reference of a motor to a rotational speed when armature current comes to a current limit or when the current comes to a previously set value. CONSTITUTION:From a speed controlling amplifier 8, the output of current command signal according to a deviation between a speed reference via an acceleration or deceleration rate limit circuit 7 and speed detecting signal from a speed detector 16 is generated. By a current controlling amplifier 12, a deviation between current command signal via a current rate limit circuit 10 and a current limit circuit 11, and current detecting signal from an armature current detector 9 is applied to a phase unit 13. In the meantime, by a speed reference regulating amplifier 20, speed reference regulating signal lowering the speed reference to a rotational speed which can drive at a set current value is added to the speed reference set at a speed setting unit 6, when the current detecting signal exceeds the set current value. |
