Patent ID: 8198844
Filing Date: 2012-06-12
Classification: H02P

Abstract:
1. A motor speed controller, comprising: a feedforward control section for receiving a target setting value that sets the magnitude and direction of a target rotational speed of a motor, generating a target instruction signal on the basis of the target setting value, and performing feedforward control so as to bring the rotational speed of the motor to the target rotational speed; a feedback control section for generating an error signal that corresponds to the difference between the current rotational speed and the target rotational speed, generating a compensation instruction signal on the basis of the error signal, and performing feedback control so as to adjust the rotational speed to the target rotational speed; a drive control section for generating a composite signal by combining the target instruction signal and the compensation instruction signal, and controlling the driving of the motor on the basis of the composite signal; and an out-of-control reverse rotation determining section for determining that the motor is in a state of out-of-control reverse rotation in which the motor rotates out of control in the reverse of the direction of the target rotational speed in the case when the compensation instruction signal or the composite signal is used as a monitored signal, and a state continues for a designated period in which the control direction of the monitored signal with respect to the rotational speed is the reverse of the direction of the target rotational speed, and in which the strength of the monitored signal exceeds a designated threshold.