Motor drive apparatus, electric actuator and electric power steering apparatus

摘要

The present invention relates to an actuator which is in an operation range subjected to quick acceleration and deceleration, a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area. A controller (3) comprises a voltage saturation detecting means (52) for detecting the voltage saturation WO of the output voltage of an inverter circuit (1), based on the battery voltage Ed, and a waveform controller (51) that converts the drive waveform of the inverter circuit (1) into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWM carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation WO detected by a voltage saturation detecting means (52). This arrangement allows the controller (3) to continuously change the drive waveform of the inverter circuit (1).