A motor control device that controls a motor based on the back EMF voltage of the motor winding

Abstract

The invention discloses a motor control apparatus for controlling a motor based on counter-electromotive voltage generated in winding of the motor. The motor control apparatus includes: a unit configured to determine a counter-electromotive voltage in a winding of a motor; a unit configured to determine a rotational position of a rotor of the motor based on the counter-electromotive voltage; a unit configured to determine a first velocity of the rotor, based on change in the rotational position; a correction unit configured to obtain a second velocity by correcting the first velocity based on a harmonic component included in the first velocity; and a driving unit configured to drive the motor based on the second velocity and the rotational position. The correction unit includes a unit configured to obtain the second velocity by reducing error in the first velocity that occurs due to the harmonic component.

Description

technical field [0001] The invention relates to a motor control device for controlling a motor. Background technique [0002] Permanent magnet motors (hereinafter also simply referred to as "motors") are excellent for achieving compact size and high efficiency, and are used as drive units in various fields including information equipment fields such as printers and copiers. When vector control is used as motor control, torque generated in the motor can be more precisely controlled, and higher efficiency, noise reduction, and vibration reduction in the motor can be achieved. Information about the rotational position of the rotor of the motor is required in vector control. Therefore, generally, a position sensor such as a Hall element or an encoder is used, which leads to an increase in cost and size. [0003] In view of this, a sensorless method has been proposed in which the rotational position of the rotor is estimated based on the current flowing into the motor without u...

AI Technical Summary

Problems solved by technology

[0005] However, with the configuration disclosed in Japanese Patent No. 5170505, a phase lag caused by the low-pass filter occurs, and a lag occurs in the estimation of the rotational position and the rotational speed of the rotor

Due to this hysteresis, the responsiveness and stability of the control loop decreases

With the configuration disclosed in Japanese Patent No. 4154149, phase lag does not occur, but in order to obtain back EMF voltage data, measurement using a dedicated device needs to be performed in advance, which reduces productivity

With the configuration disclosed in Japanese Patent No. 4631672, the extracted harmonic components include those generated from counter-EMF voltage distortion and those that appear due to speed changes and load changes, and there is no distinction between these harmonic components , therefore, the error is included in the calculated correction for the rotational position

It is also difficult to eliminate the effect of the phase shift caused by the high-pass filter, and the error caused by the phase shift will also appear

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