Motor control device and motor control method

Patent metadata

Field	Value
Publication number	US-9312799-B2
Application number	US-201214351232-A
Country	US
Kind code	B2
Filing date	Oct 3, 2012
Priority date	Oct 21, 2011
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

This motor control device generates a voltage command value from a current command value and performs feedback control by means of a detected current flowing through a motor. The motor control device is provided with: a speed control unit that causes the motor to rotate at a set speed, and performs speed control of the motor on the basis of a speed command value that causes the flow of a d-axis current that is a set amount of current; a current measurement unit that measures a current command value that is on the basis of the output of the speed control unit when the motor is rotated at the set speed and the set amount of d-axis current is flowing; and a correction value calculation unit that calculates a correction value for the rotational position of the motor on the basis of the measured current command value.

First claim

The invention claimed is:

1. A motor control device generating a voltage command value from a current command value and performing feedback control using a detection current flowing in a motor, the motor control device comprising:
a velocity control unit configured to perform velocity control of the motor based on a velocity command value by which a constant current amount of d-axis current flows by rotating the motor at a constant velocity;
a current measurement unit configured to measure the current command value based on an output of the velocity control unit when the motor is rotated at the constant velocity and the constant current amount of d-axis current flows; and
a correction value calculation unit configured to calculate a correction value at a rotation position of the motor based on the measured current command value, wherein
the current command value includes a d-axis current command value and a q-axis current command value,
the current measurement unit measures the d-axis current command value and the q-axis current command value when the motor is rotated based on the velocity command value, and
the correction value calculation unit calculates a first correction value based on phases of the measured d-axis current command value and q-axis current command value when the motor is positively rotated,
the correction value calculation unit calculates a second correction value calculated based on the phases of the measured d-axis current command value and q-axis current command value when the motor is negatively rotated,
the velocity control unit performs control such that an absolute value of the velocity command value in the positive rotation of the motor is the same as an absolute value of the velocity command value in the negative rotation of the motor, and
the correction value calculation unit calculates the correction value by calculating an average of the calculated first and second correction values.

2. The motor control device according to claim 1 , wherein
the correction value calculation unit generates a value indicating the rotation position by adding the calculated correction value and a detection value corresponding to the rotation position of the motor, and
the velocity control unit controls the motor based on the generated value indicating the rotation position.

3. The motor control device according to claim 1 , wherein, when the current measurement unit measures the current command value, the velocity control unit performs the velocity control of the motor based on the velocity command value by which the constant current amount of d-axis current flows in the motor in a field-weakening control region.

4. The motor control device according to claim 1 , wherein, when the current measurement unit measures the current command value, the velocity control unit performs the velocity control of the motor based on a current command value obtained by adding the constant current amount of d-axis current and the current command value in a control region in which a velocity of the motor is not within a field-weakening region.

5. The motor control device according to claim 1 , wherein the correction value calculation unit calculates the correction value, the first correction value, and the second correction value using an equation below:

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CURRENT

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6. The motor control device according to claim 1 , wherein
the current measurement unit measures the q-axis current command value when the motor is rotated based on the velocity command value, and
the correction value calculation unit repeatedly calculates the correction value by performing proportional integral control so that the measured q-axis current command value becomes 0 and performs addition to the detection value corresponding to the rotation position of the motor based on the calculated correction value.

7. A motor control method of a motor control device generating a voltage command value from a current command value and performing feedback control using a detection current flowing in a motor, the motor control method comprising:
a velocity control procedure of performing, by a velocity control unit, velocity control of the motor based on a velocity command value by which a constant current amount of d-axis current flows by rotating the motor at a constant velocity;
a current measurement procedure of measuring, by a current measurement unit, the current

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Kato Yoshiki

Classifications

• H02P21/16

  Estimation of constants, e.g. the rotor time constant · CPC title

• H02P21/18

  Estimation of position or speed · CPC title

• H02P21/0089 Primary

  using field weakening · CPC title

• H02P21/0085 Primary

  specially adapted for high speeds, e.g. above nominal speed · CPC title

• H02P21/0096 Primary

  Electricity · mapped topic