Motor control device and motor control method

Abstract

In a motor control device, a two-phase/three-phase converter is configured to convert a d-axis voltage instruction and a q-axis voltage instruction into voltage instructions in UVW phases. A PWM circuit is configured to generate drive pulse signals having undergone power width modulation, in accordance with the voltage instructions. An inverter is configured to generate drive voltages for driving coils based on the drive pulse signals. A position detector is configured to detect a rotational position. A rotational speed calculator is configured to calculate a rotational speed. A current detector is configured to detect drive currents flowing into the coils. A three-phase/two-phase converter is configured to convert detected drive current values into a d-axis current value and a q-axis current value. A d-axis voltage instruction generation unit is configured to acquire a difference between the d-axis current value and a d-axis current instruction having a predetermined value, and to generate the d-axis voltage instruction based on PI computation performed on the difference. A q-axis voltage instruction generation unit is configured to acquire a difference between a speed instruction and the rotational speed calculated by a rotational speed calculation unit, and to generate the q-axis voltage instruction based on PI computation performed on the difference.