MOTOR DRIVE CIRCUIT AND PERMANENT MAGNET SYNCHRONOUS MOTOR

摘要

A motor control circuit 1 according to the present invention includes a magnetic-pole-position detecting unit 11 that detects a rotating position of a rotor 9 of a permanent magnet synchronous motor 7, a voltage output unit 3 that converts a direct-current voltage and generates a driving voltage for the permanent magnet synchronous motor 7, a voltage control unit 5 that generates a modulation wave on the basis of the rotating position and a rotating speed control signal for controlling rotating speed of the rotor 9 and controls the voltage output unit 3 on the basis of a comparison result of the modulation wave and a carrier wave, a voltage-phase adjusting unit 12 that determines, on the basis of the rotating speed control signal and an offset signal, a phase of the modulation wave generated by the voltage control unit 5 and causes the voltage control unit 5 to generate the modulation wave in the determined phase, and an offset generating unit 13 that generates the offset signal. The voltage-phase adjusting unit 12 determines the phase with a differential amplifier circuit that receives the rotating speed control signal and the offset signal as inputs.