Control device for alternating-current electric motor and electric vehicle equipped with the same, and electric aircraft

Patent metadata

Field	Value
Publication number	US-2025211149-A1
Application number	US-202318848551-A
Country	US
Kind code	A1
Filing date	May 16, 2023
Priority date	Aug 4, 2022
Publication date	Jun 26, 2025
Grant date	—

Abstract

The control device controls an alternating-current electric motor via an inverter based on angle information of a position sensor. The position sensor is set such that the ratio between the number of polar pairs of the alternating-current electric motor and the axial double angle X of the position sensor is an integer multiple. The control device includes an electrical angle phase calculation unit that multiplies angle information detected by the position sensor by an integer multiple and converts the multiplied angle information into electrical angle phase information, an electrical angle rotation number calculation unit that calculates an electrical angle rotation number based on the electrical angle phase information calculated by the electrical angle phase calculation unit, and a vector control unit that calculates a voltage command value to be output to the inverter based on the electrical angle phase information.

First claim

1 . A control device for an alternating-current electric motor that controls an alternating-current electric motor via an inverter based on angle information of a position sensor that detects an angular position of the alternating-current electric motor, wherein
the position sensor is set such that a ratio between a number of polar pairs of the alternating-current electric motor and an axial double angle X of the position sensor is an integer multiple, and the control device includes,
an electrical angle phase calculation unit that multiplies angle information of the alternating-current electric motor detected by the position sensor by the integer multiple and converts the multiplied angle information into electrical angle phase information of the alternating-current electric motor,
an electrical angle rotation number calculation unit that calculates an electrical angle rotation number of the alternating-current electric motor based on the electrical angle phase information of the alternating-current electric motor calculated by the electrical angle phase calculation unit, and
a vector control unit that calculates a voltage command value to be output to the inverter based on the electrical angle phase information of the alternating-current electric motor calculated by the electrical angle phase calculation unit and the electrical angle rotation number of the alternating-current electric motor calculated by the electrical angle rotation number calculation unit.

2 . The control device for the alternating-current electric motor according to claim 1 , wherein
the electrical angle rotation number calculation unit is an electrical angle phase/rotation number calculation unit having a function of calculating a control phase of the alternating-current electric motor based on electrical angle phase information of the alternating-current electric motor calculated by the electrical angle phase calculation unit, and the electrical angle phase/rotation number calculation unit includes,
a phase difference calculation unit that calculates an electrical angle phase difference that is a difference between the electrical angle phase information and the control phase,
a filter processing unit configured to reduce, based on the electrical angle phase difference calculated by the phase difference calculation unit, information on the number of polar pairs of the alternating-current electric motor and the axial double angle X of the position sensor, and the electrical angle rotation number of the alternating-current electric motor, a frequency component obtained by integer multiplying the mechanical rotation number of the alternating-current electric motor by an axial double angle X;
a speed estimation unit that estimates an electrical angle rotation number of the alternating-current electric motor based on the electrical angle phase difference filter processed by the filter processing unit; and
a control phase calculation unit that calculates a control phase used by the vector control unit based on the electrical angle rotation number of the alternating-current electric motor calculated by the speed estimation unit.

3 . The control device for the alternating-current electric motor according to claim 2 , further comprising
a phase difference switching unit that switches whether an electrical phase difference input to the speed estimation unit is an electrical angle phase difference from the phase difference calculation unit or an electrical angle phase difference filter processed by the filter processing unit according to the rotation number of the alternating-current electric motor.

4 . The control device for the alternating-current electric motor according to claim 3 , wherein the phase difference switching unit selects the electrical angle phase difference of the phase difference calculation unit when the rotation number of the alternating-current electric motor is lower than a predetermined value, and selects the electrical angle phase difference filter processed by the filter processing unit when the rotation number of the alternating-current electric motor is higher than the predetermined value.

5 . The control device for the alternating-current electric motor according to claim 3 , wherein
the phase difference switching unit includes a predetermined lower limit value of the rotation number of the alternating-current electric motor and a predetermined upper limit value set to a rotation number higher than the predetermined lower limit value, selects an electrical angle phase difference of the phase difference calculation unit when the rotation number of the alternating-current electric motor is lower than the predetermined lower limit value, and selects an electrical angle phase difference filter processed by the filter processing unit when the rotation number of the alternating-current electric motor is higher than the predetermined upper limit value, and when the rotation number of the alternating-current electric motor is between the predetermined lower limit value and the predetermined upper limit value, an electrical angle phase difference output from the phase difference calculation unit according to a ratio of a difference between the predetermined lower limit value and the rotation number of the alternating-current electric motor and a difference between the predetermined lower limit value and the predetermined upper limit value, and an electrical angle phase difference after filter processing output from the filter processing unit are output in a tapered manner according to the ratio.

6 . An electric vehicle including a control device for an alternating-current electric motor that is disposed on a wheel in the alternating-current electric motor and controls the alternating-current electric motor, the electric vehicle comprising
a control device for alternating-current electric motor according to claim 1 .

7 . An electric aircraft including a control device for an alternating-current electric motor that is disposed on a propulsion fan in the alternating-current electric motor and controls the alternating-current electric motor, the electric aircraft comprising
a control device for the alternating-current electric motor according to claim 1 .

Assignees

• Hitachi Ltd

Inventors

• Hatsuse Wataru
• Hara Takafumi
• Ajima Toshiyuki

Classifications

• H02P27/06

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02P21/18 Primary

  Estimation of position or speed · CPC title

• H02P6/16 Primary

  Circuit arrangements for detecting position · CPC title