Electric motor control device

Patent metadata

Field	Value
Publication number	US-12068702-B2
Application number	US-202017920607-A
Country	US
Kind code	B2
Filing date	May 19, 2020
Priority date	May 19, 2020
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

In an electric motor control device which controls rotation of an AC electric motor having two sets of three-phase windings and provided with a resolver having two systems by calculating voltage command values on dq axes, dq conversion of currents of first three-phase windings is performed using a first angle calculated from output of the first system of the resolver, and dq conversion of currents of second three-phase windings is performed using a second angle calculated from output of the second system of the resolver. With both d-axis current command values set at the same value, respective voltage command values on dq axes are calculated and respectively converted into voltage command values for voltage application to the first three-phase windings, using the first angle, and converted into voltage command values for voltage application to the second three-phase windings, using the second angle.

First claim

The invention claimed is:

1. An electric motor control device configured to control rotation of an AC electric motor having first three-phase windings and second three-phase windings and provided with a resolver in which a plurality of teeth provided to a stator are wound with a first excitation winding and a first output winding as a first system and a second excitation winding and a second output winding as a second system such that a number of the teeth wound with the windings in the first system and a number of the teeth wound with the windings in the second system are equal to each other, the electric motor control device comprising:
a first voltage application circuitry which applies AC voltages for three phases to the first three-phase windings;
a second voltage application circuitry which applies AC voltages for three phases to the second three-phase windings;
a first current detector which detects current for each phase of the first three-phase windings;
a second current detector which detects current for each phase of the second three-phase windings; and
a controller which outputs AC voltage to be applied to the first excitation winding and AC voltage to be applied to the second excitation winding, calculates first voltage command values which are voltage command values for three phases in the first voltage application circuitry and outputs the first voltage command values to the first voltage application circuitry, and calculates second voltage command values which are voltage command values for three phases in the second voltage application circuitry and outputs the second voltage command values to the second voltage application circuitry, wherein
the controller is configured to
perform coordinate conversion of current values for three phases detected by the first current detector into a first d-axis current value and a first q-axis current value, using a first angle obtained from an output of the first system of the resolver, and perform coordinate conversion of current values for three phases detected by the second current detector into a second d-axis current value and a second q-axis current value, using a second angle obtained from an output of the second system of the resolver,
select either a first d-axis current command value candidate calculated from a first current command value inputted as a current command value for the first three-phase windings or a second d-axis current command value candidate calculated from a second current command value inputted as a current command value for the second three-phase windings, and set the selected one as a d-axis current command value,
calculate a first d-axis voltage command value so that the d-axis current command value and the first d-axis current value coincide with each other, calculate a first q-axis voltage command value so that a first q-axis current command value obtained from the first current command value and the first q-axis current value coincide with each other, and perform coordinate conversion of the first d-axis voltage command value and the first q-axis voltage command value, using the first angle, to calculate the first voltage command values, and
calculate a second d-axis voltage command value so that the d-axis current command value and the second d-axis current value coincide with each other, calculate a second q-axis voltage command value so that a second q-axis current command value obtained from the second current command value and the second q-axis current value coincide with each other, and perform coordinate conversion of the second d-axis voltage command value and the second q-axis voltage command value, using the second angle, to calculate the second voltage command values.

2. An electric motor control device configured to control rotation of an AC electric motor having first three-phase windings and second three-phase windings and provided with a resolver in which a plurality of teeth provided to a stator are wound with a first excitation winding and a first output winding as a first system and a second excitation winding and a second output winding as a second system such that a number of the teeth wound with the windings in the first system and a number of the teeth wound with the windings in the second system are equal to each other, the electric motor control device comprising:
a first voltage application circuitry which applies AC voltages for three phases to the first three-phase windings;
a second voltage application circuitry which applies AC voltages for three phases to the second three-phase windings;
a first current detector which detects current for each phase of the first three-phase windings;
a second current detector which detects current for each phase of the second three-phase windings; and
a controller which outputs AC voltage to be applied to the first excitation winding and AC voltage to be applied to the second excitation winding, calculates first voltage command values which are voltage command values for three phases in the first voltage application circuitry and outputs the first voltage command values to the first voltage application circuitry, and calculates second voltage command values which are voltage command values for three phases in the second voltage application circuitry and outputs the second voltage command values to the second voltage application circuitry, wherein
the controller is configured to
perform coordinate conversion of current values for three phases detected by the first current detector into a first d-axis current value and a first q-axis current value, and coordinate conversion of current values for three phases detected by the second current detector into a second d-axis current value and a second q-axis current value, using a corrected angle set as an average value of a first angle obtained from an output of the first system and a second angle obtained from an output of the second system of the resolver,
calculate a first d-axis voltage command value so that a first d-axis current command value obtained from a first current command value inputted as a current command value for the first three-phase windings and the first d-axis current value coincide with each other, calculate a first q-axis voltage command value so that a first q-axis current command value obtained from the first current command value and the first q-axis current value coincide with each other, and perform coordinate conversion of the first d-axis voltage command value and the first q-axis voltage command value, using the corrected angle, to calculate the first voltage command values, and
calculate a second d-axis voltage command value so that a second d-axis current command value obtained from a second current command value inputted as a current command value for the second three-phase windings and the second d-axis current value coincide with each other, calculate a second q-axis voltage command value so that a second q-axis current command value obtained from the second current command value and the second q-axis current value coincide with each other, and perform coordinate conversion of the second d-axis voltage command value and the second q-axis voltage command value, using the corrected angle, to calculate the second voltage command values.

3. An electric motor control device configured to control rotation of an AC electric motor having first three-phase windings and second three-phase windings and provided with a resolver in which a plurality of teeth provided to a stator are wound with a first excitation winding and a first output winding as a first system and a second excitation winding and a second output winding as a second system such that a number of the teeth wound with the windings in the first system and a number of the teeth wound with the windings in the second system are equal to each other, the electric motor control dev

Assignees

• Mitsubishi Electric Corp

Inventors

• ORII Masahiko
• Mori Tatsuya
• Ikeda Hiroko
• Matsunaga Toshihiro
• Ikeda Kenji
• Kubo Kenta

Classifications

• H02P25/22 Primary

  Multiple windings; Windings for more than three phases · CPC title

• H02P21/05

  specially adapted for damping motor oscillations, e.g. for reducing hunting · CPC title

• H02P6/16

  Circuit arrangements for detecting position · CPC title

• H02P6/10

  Arrangements for controlling torque ripple, e.g. providing reduced torque ripple · CPC title

• G01D3/02

  with provision for altering or correcting the law of variation · CPC title