Motor control apparatus and method

摘要

A motor control apparatus includes an inverter for applying voltage to a synchronous motor and a control apparatus 4 for calculating a voltage instruction value to be applied by a PWM signal. There are provided a current difference sensing unit of the synchronous motor, a current difference calculation unit for calculating a current change attributed to the voltage applied, and a position sensing unit for estimating a counter electromotive force direction according to the current change sensed by the current change sensing unit and the current change calculated by the current difference calculation unit. The magnetic pole position of the rotor of the synchronous motor is estimated according to the counter electromotive force direction estimated by the position sensing unit and the voltage applied to the synchronous motor is controlled according to the estimated magnetic pole position.