Motor driving device and vacuum pump

摘要

A motor driving device comprises: an inverter having a plurality of switching elements for driving a motor; an arithmetic section for calculating a rotational speed and a magnetic pole electric angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current; a delay correcting section for correcting a phase delay of the magnetic pole electric angle calculated by the arithmetic section so as to generate corrected magnetic pole electric angle; a driving command generating section for generating a sinusoidal wave driving command based on a difference between the rotational speed and a target rotational speed and the corrected magnetic pole electric angle; and a PWM signal generating section for generating a PWM control signal for controlling on/off of the plurality of switching elements based on the sinusoidal wave driving command.

主权项

1. A motor driving device comprising:
an inverter having a plurality of switching elements for driving a motor; an arithmetic section for calculating a rotational speed and a magnetic pole electric angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current; at least one low-pass filter for removing noise of at least one of the motor phase voltage and the motor phase current; a delay correcting section for correcting a phase delay of the magnetic pole electric angle calculated by the arithmetic section so as to generate a corrected magnetic pole electric angle, the phase delay being predetermined based on filter characteristics of the at least one low-pass filter; a driving command generating section for generating a sinusoidal wave driving command based on a difference between the rotational speed and a target rotational speed and the corrected magnetic pole electric angle; and a PWM signal generating section for generating a PWM control signal for controlling on/off of the plurality of switching elements based on the sinusoidal wave driving command, wherein the information about the motor phase voltage is a motor phase voltage detection signal input via a first low-pass filter included in the at least one low-pass filter, and the information about the motor phase current is a motor phase current detection signal input via a second low-pass filter included in the at least one low-pass filter, filter characteristics of the second low-pass filter are set so as to be identical to filter characteristics of the first low-pass filter, and the delay correcting section calculates a leading phase for correcting a phase delay caused by the filter characteristics of the first low-pass filter, and adds the leading phase to the magnetic pole electric angle so as to generate the corrected magnetic pole electric angle.