Patent ID: 8536812
Filing Date: 2013-09-17
Classification: H02P

Abstract:
1. A motor control device comprising: an electric power supply unit which supplies AC current to an electric motor driving a load; a current detecting unit which detects current flowing into a winding of the motor; a speed/electrical angle estimating unit which estimates a rotational speed and an electrical angle of the motor, based on the current detected by the current detecting unit; a load torque estimating unit which estimates a load torque to be produced by the load, from a torque current obtained based on the current detected by the current detecting unit and the electrical angle estimated by the speed/electrical angle estimating unit, a motor constant and inertia moment of the motor inclusive of the load; a load torque phase calculating unit which calculates a phase of periodic fluctuation indicated by the load torque; a torque-compensating current determining unit which determines a sinusoidal torque compensating current, based on the load torque phase; and an amplitude/phase adjusting unit which detects a speed fluctuation of the motor to adjust an amplitude and a phase of the torque-compensating current by increasing or decreasing the amplitude and the phase so that the speed fluctuation is reduced.