Control device of AC rotating machine and electric power steering device

• US 10,439,535 B2
• Filed: 04/27/2015
• Issued: 10/08/2019
• Est. Priority Date: 04/27/2015
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Mori, Tatsuya, Nakajima, Shunsuke, Kezobo, Isao
• Primary Examiner(s): Carrasquillo, Jorge L
• Assistant Examiner(s): Joseph, Devon A
• Application Number:
  US15/569,136
• Publication Number:
  US 20180294755A1
• Time in Patent Office: 1,625 Days
• Field of Search: 318400
• CPC Class Codes: B62D 5/0463 calculating assisting torque from the motor based on driver input
• CPC Class Codes: H02P 21/18 Estimation of position or speed
• CPC Class Codes: H02P 21/22 Current control, e.g. using a current control loop
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 27/16 using ac to ac converters without intermediate conversion to dc H02P27/05 takes precedence
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence
• CPC Class Codes: H02P 6/18 without separate position detecting elements

Abstract

This invention is concerning a control device of an AC rotating machine that estimates, as an estimated rotational position, a rotational position of an AC rotating machine having N sets of three-phase windings where N is a natural number equal to or greater than 2, the device being made up of: a voltage sum calculator that calculates a voltage sum from N sets of voltage commands for applying AC voltage to the N sets of three-phase windings; a current sum calculator that calculates a current sum from N sets of currents respectively flowing in the N sets of three-phase windings; and a rotational position estimator that calculates an estimated rotational position on the basis of calculation results of the voltage sum calculator and the current sum calculator.

Claims

1. A control device of an AC rotating machine estimating, as an estimated rotational position, a rotational position of the AC rotating machine having N sets of three-phase windings, where N is a natural number equal to or greater than 2,

the control device comprising:

a current detector that detects and outputs N sets of currents respectively flowing in N sets of three-phase windings;

a controller that calculates and outputs respective N sets of voltage commands for the N sets of three-phase windings on the basis of a control command for the AC rotating machine and the N sets of currents input from the current detector; and

a power converter that applies AC voltage to the N sets of three-phase windings on the basis of the input N sets of voltage commands, wherein

the controller has

a voltage sum calculator that calculates and outputs a voltage sum from the input N sets of voltage commands;

a current sum calculator that calculates and outputs a current sum from the input N sets of currents; and

a rotational position estimator that calculates the estimated rotational position on the basis of the input voltage sum and the input current sum,

wherein the voltage sum calculator calculates, as the voltage sum, a value resulting from multiplying, by N, any one of the N sets of voltage commands; and

the current sum calculator calculates, as the current sum, a value resulting from adding each of the N sets of currents.

2. The control device of the AC rotating machine claim 1, wherein

N is 2,

the AC rotating machine has first three-phase windings and second three-phase windings, as two sets of three-phase windings,

the current detector is made up of:

a first current detector that detects first three-phase winding currents flowing in the first three-phase windings; and

a second current detector that detects second three-phase winding currents flowing in the second three-phase windings,

the controller calculates a first three-phase voltage command for the first three-phase windings and a second three-phase voltage command for the second three-phase windings on the basis of the control command for the AC rotating machine, and on the basis of first three-phase winding currents and second three-phase winding currents input as two sets of currents, and

the power converter is made up of;

a first power converter that applies the AC voltage to the first three-phase windings on the basis of the input first three-phase voltage command; and

a second power converter that applies the AC voltage to the second three-phase windings on the basis of the input second three-phase voltage command.

3. The control device of the AC rotating machine of claim 2, wherein when n is a natural number equal to or greater than 4,

the controller calculates the first three-phase voltage command and the second three-phase voltage command so that a phase of the first three-phase voltage command and a phase of the second three-phase voltage command are shifted by only (180/n) degrees from each other.

4. The control device of the AC rotating machine of claim 2, wherein

the AC rotating machine is a permanent magnet synchronous rotating machine;

and

when n is a natural number equal to or greater than 4 and m is a natural number,

there is a phase difference of (180/n) degrees between the first three-phase windings and the second three-phase windings, and

an (n×

m±

1)-th order component is included in first three-phase induced voltages that are induced in the first three-phase windings and in second three-phase induced voltages that are induced in the second three-phase windings, as a result of the rotation of the AC rotating machine.

5. The control device of the AC rotating machine of claim 2,

wherein the first three-phase windings and the second three-phase windings are magnetically coupled to each other.

6. An electric power steering device, comprising:

the control device of the AC rotating machine of claim 1;

a torque detector that detects steering torque; and

a control command calculator that calculates a control command for the AC rotating machine on the basis of the steering torque detected by the torque detector, so that the AC rotating machine generates torque that assists the steering torque.

7. A control device of an AC rotating machine estimating, as an estimated rotational position, a rotational position of the AC rotating machine having N sets of three-phase windings, where N is a natural number equal to or greater than 2,

the control device comprising:

a current detector that detects and outputs N sets of currents respectively flowing in N sets of three-phase windings;

a controller that calculates and outputs respective N sets of voltage commands for the N sets of three-phase windings on the basis of a control command for the AC rotating machine and the N sets of currents input from the current detector; and

a power converter that applies AC voltage to the N sets of three-phase windings on the basis of the input N sets of voltage commands, wherein

the controller has

a voltage sum calculator that calculates and outputs a voltage sum from the input N sets of voltage commands;

a current sum calculator that calculates and outputs a current sum from the input N sets of currents; and

a rotational position estimator that calculates the estimated rotational position on the basis of the input voltage sum and the input current sum, wherein

the voltage sum calculator calculates, as the voltage sum, a value resulting from adding each of the N sets of voltage commands; and

the current sum calculator calculates, as the current sum, a value resulting from multiplying, by N, any one of the N sets of currents.

8. A control device of an AC rotating machine estimating, as an estimated rotational position, a rotational position of the AC rotating machine having N sets of three-phase windings, where N is a natural number equal to or greater than 2,

the control device comprising:

a current detector that detects and outputs N sets of currents respectively flowing in N sets of three-phase windings;

a controller that calculates and outputs respective N sets of voltage commands for the N sets of three-phase windings on the basis of a control command for the AC rotating machine and the N sets of currents input from the current detector; and

a power converter that applies AC voltage to the N sets of three-phase windings on the basis of the input N sets of voltage commands, wherein

the controller has

a voltage sum calculator that calculates and outputs a voltage sum from the input N sets of voltage commands;

a current sum calculator that calculates and outputs a current sum from the input N sets of currents; and

a rotational position estimator that calculates the estimated rotational position on the basis of the input voltage sum and the input current sum, wherein the controller has

a current coordinate converter that calculates and outputs N sets of d-axis currents and N sets of q-axis currents respectively flowing in the N sets of three-phase windings, by coordinate conversion of the input N sets of currents into two rotating axes on the basis of the estimated rotational position;

a current controller that calculates and outputs N sets of d-axis voltage commands and N sets of q-axis voltage commands, as the N sets of voltage commands, on the basis of the control command for the AC rotating machine, and on the basis of the input N sets of d-axis currents and N sets of q-axis currents; and

a voltage coordinate converter that calculates and outputs N sets of three-phase voltage commands by coordinate conversion into two rotating axes of the input N sets of d-axis voltage commands and N sets of q-axis voltage commands on the basis of the estimated rotational position, and wherein

the voltage sum calculator

calculates, as the voltage sum, a d-axis voltage sum from the N sets of d-axis voltage commands and a q-axis voltage sum from the N sets of q-axis voltage commands, respectively; and

the current sum calculator calculates, as the current sum, a d-axis current sum from the N sets of d-axis currents and a q-axis current sum from the N sets of q-axis currents, respectively.

9. The control device of the AC rotating machine of claim 8, wherein

the voltage sum calculator calculates, as the voltage sum, a value resulting from adding each of the N sets of voltage commands;

and

the current sum calculator calculates, as the current sum, a value resulting from adding each of the N sets of currents.