Controller for rotary electric machine and electric power steering apparatus

Patent metadata

Field	Value
Publication number	US-12528535-B2
Application number	US-202018028284-A
Country	US
Kind code	B2
Filing date	Nov 30, 2020
Priority date	Nov 30, 2020
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

To provide a controller for rotary electric machine and an electric power steering apparatus which can set a control gain which is used for controlling the d-axis current command value based on the q-axis current deviation between the current command value of q-axis and the current detection value of q-axis, considering the response of the current of q-axis. A controller for rotary electric machine changes the current command value of d-axis, based on a value obtained by multiplying a proportional gain to a q-axis current deviation which is a deviation between the current command value of q-axis and the current detection value of q-axis; and changes the proportional gain in inverse proportion to the rotational angle speed.

First claim

What is claimed is:

1 . A controller for a rotary electric machine that controls the rotary electric machine which is provided with a stator having plural-phase windings and a rotor having a magnet via an electric power converter, the controller for the rotary electric machine comprising at least one processor configured to implement:
a current detector that detects currents which flows into the plural-phase windings; a current coordinate convertor that converts current detection values into a current detection value of d-axis and a current detection value of q-axis on a dq-axis rotating coordinate system consisting of a d-axis defined in a direction of a magnetic pole position of the rotor and a q-axis defined in a direction advanced to the d-axis by 90 degrees in an electrical angle, based on a rotational angle of the rotor; a current command value calculator that calculates a current command value of d-axis and a current command value of q-axis; a voltage command value calculator that changes a voltage command value of d-axis and a voltage command value of q-axis so that the current detection value of d-axis approaches the current command value of d-axis, and the current detection value of q-axis approaches the current command value of q-axis; and converts the voltage command value of d-axis and the voltage command value of q-axis into voltage command values of plural-phase, based on the rotational angle; and a switching controller that turns on and off a plurality of switching devices provided in the electric power converter, based on the voltage command values of plural-phase, wherein the current command value calculator changes the current command value of d-axis, based on a value obtained by multiplying a proportional gain to a q-axis current deviation which is a deviation between the current command value of q-axis and the current detection value of q-axis; and changes the proportional gain in inverse proportion to a rotational angle speed of the rotor.

2 . The controller for the rotary electric machine according to claim 1 ,
wherein the current command value calculator changes the current command value of d-axis, based on the q-axis current deviation; and sets a value obtained by dividing a target response angular frequency of a feedback control system which decreases an absolute value of the q-axis current deviation by the rotational angle speed, as the proportional gain.

3 . The controller for the rotary electric machine according to claim 2 ,
wherein the current command value calculator sets the target response angular frequency to a value larger than a value obtained by dividing a resistance value of winding by an inductance.

4 . The controller for the rotary electric machine according to claim 2 ,
wherein the voltage command value calculator calculates the voltage command value of d-axis, based on a value obtained by multiplying a proportional gain of d-axis to a d-axis current deviation which is a deviation between the current command value of d-axis and the current detection value of d-axis; and sets the proportional gain of d-axis to a value larger than a value obtained by multiplying an inductance to the target response angular frequency.

5 . The controller for the rotary electric machine according to claim 1 ,
wherein the current command value calculator calculates the current command value of d-axis, based on a total value of the value obtained by multiplying the proportional gain to the q-axis current deviation, and an integration value of a value obtained by multiplying an integral gain to the q-axis current deviation; and changes the integral gain in inverse proportion to the rotational angle speed.

6 . The controller for the rotary electric machine according to claim 5 ,
wherein the current command value calculator changes the current command value of d-axis, based on the q-axis current deviation; and sets a value obtained by dividing a target response angular frequency of a feedback control system which decreases an absolute value of the q-axis current deviation by the rotational angle speed, as the proportional gain; and sets a value obtained by dividing a value obtained by multiplying a resistance value of winding to the target response angular frequency, by the rotational angle speed and an inductance, as the integral gain.

7 . The controller for the rotary electric machine according to claim 1 ,
wherein the current command value calculator calculates the q-axis current deviation by a deviation between a current command value of q-axis after offset obtained by decreasing an absolute value of the current command value of q-axis by a q-axis offset value, and the current detection value of q-axis.

8 . An electric power steering apparatus comprising:
the controller for the rotary electric machine according to claim 1 , the electric power converter, the rotary electric machine, and a driving force transmission mechanism which transmits a driving force of the rotary electric machine to a vehicle steering apparatus.

Assignees

• Mitsubishi Electric Corp

Inventors

• Mori Tatsuya
• Kitagawa Jun
• ORII Masahiko
• Kubo Kenta
• Sawada Kenta

Classifications

• B62D6/008

  Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications · CPC title

• H02P21/22 Primary

  Current control, e.g. using a current control loop · CPC title

• H02P21/18

  Estimation of position or speed · CPC title

• B62D5/046

  Controlling the motor · CPC title

• H02P25/03

  with brushless excitation · CPC title