Rotary electric machine apparatus

Patent metadata

Field	Value
Publication number	US-12166439-B2
Application number	US-202017796789-A
Country	US
Kind code	B2
Filing date	Mar 2, 2020
Priority date	Mar 2, 2020
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

To provide a rotary electric machine apparatus which can perform current control which reduces a torque ripple component effectively, using a rotary electric machine in which the permanent magnet of the rotor has the skew structure which shifts the magnetic pole position in the circumferential direction at each position in the axial direction. When defining, as the current vector of most advanced phase, a current vector of current command values calculated on the dq-axis rotating coordinate system of most advanced phase, and defining, as the current vector of middle phase, a current vector of current command values calculated on the dq-axis rotating coordinate system of middle phase, the rotary electric machine apparatus brings a controlling current vector close to the current vector of most advanced phase from the current vector of middle phase, as the winding currents increase.

First claim

What is claimed is:

1. A rotary electric machine apparatus comprising:
a rotary electric machine that is provided with a rotor having permanent magnets, and a stator having plural-phase windings;
an inverter that converts DC power supplied from a DC power source and AC power supplied to the plural-phase windings, and is provided with a plurality of switching devices;
a current detector that detects currents which flow into the plural-phase windings;
a rotation detector that detects a rotational angle of the rotor;
a current controller that sets a magnetic pole position for control based on a detection value of the rotational angle, calculates current command values for control, and calculates voltage command values based on detection values of the currents, the current command values for control, and the magnetic pole position for control; and
a switching controller that controls on/off the plurality of switching devices based on the voltage command values,
wherein the permanent magnets have a skew structure in which the magnetic pole positions are shifted in the circumferential direction at each position in an axial direction,
wherein when defining, as a current vector of most advanced phase, a current vector of the current command values calculated on a dq-axis rotating coordinate system of most advanced phase which consists of a d-axis defined in a direction of the magnetic pole position whose phase is most advanced in a rotation direction among the magnetic pole positions of respective positions in the axial direction, and a q-axis defined in a direction advanced to this d-axis by 90 degrees in an electrical angle, and
defining, as a current vector of middle phase, a current vector of the current command values calculated on a dq-axis rotating coordinate system of middle phase which consists of a d-axis defined in a direction of a middle phase between the magnetic pole position whose phase is most advanced and the magnetic pole position whose phase is most delayed in the rotation direction among the magnetic pole positions of respective positions in the axial direction, and a q-axis defined in a direction advanced to this d-axis by 90 degrees in an electrical angle,
the current controller brings a controlling current vector close to the current vector of most advanced phase from the current vector of middle phase, as winding currents flowing into the plurality of windings increase.

2. The rotary electric machine apparatus according to claim 1 ,
wherein as the winding currents increase, the current controller brings the magnetic pole position for control close to the magnetic pole position whose phase is most advanced in the rotation direction, from a magnetic pole position of the middle phase between the magnetic pole position whose phase is most advanced and the magnetic pole position whose phase is most delayed in the rotation direction;
calculates the current command values for control on a dq-axis rotating coordinate system for control which is set on a basis of the magnetic pole position for control; and
calculates the voltage command values based on the detection values of currents and the current command values for control.

3. The rotary electric machine apparatus according to claim 1 ,
wherein the current controller sets, as the magnetic pole position for control, a magnetic pole position of the middle phase between the magnetic pole position whose phase is most advanced and the magnetic pole position whose phase is most delayed in the rotation direction;
calculates current command values on the dq-axis rotating coordinate system of middle phase which is set on a basis of the magnetic pole position of the middle phase;
calculates the current command values for control by decreasing a d-axis component of the current command values by a d-axis current decrease amount;
makes the d-axis current decrease amount increase so that a current vector of the current command values for control approaches the current vector of most advanced phase from the current vector of middle phase, as the winding currents increase; and
calculates the voltage command values based on the detection values of currents and the current command values for control, on the dq-axis rotating coordinate system of middle phase.

4. The rotary electric machine apparatus according to claim 1 ,
wherein when the winding currents exceed a threshold value which is set to a value smaller than an upper limit current value, the current controller brings a current vector of the current command values for control close to the current vector of middle phase from the current vector of most advanced phase, as the winding currents approach the upper limit current value.

5. The rotary electric machine apparatus according to claim 1 ,
wherein the rotary electric machine is rotatable to one side and the other side, and
wherein the current controller sets the magnetic pole position whose phase is most advanced and the magnetic pole position whose phase is most delayed in the rotation direction, according to the rotation direction of one side or the other side.

6. The rotary electric machine apparatus according to claim 5 ,
wherein the rotary electric machine is used for a driving force source of an electric power steering apparatus.

7. The rotary electric machine apparatus according to claim 1 ,
wherein the permanent magnets are provided on a surface of the rotor, and
wherein when defining, as the current vector of most advanced phase, a current vector of current command values calculated by Id=0 control on the dq-axis rotating coordinate system of most advanced phase, and
defining, as the current vector of middle phase, a current vector of current command values calculated by the Id=0 control on the dq-axis rotating coordinate system of middle phase,
the current controller brings the controlling current vector close to the current vector of most advanced phase from the current vector of middle phase, as the winding currents increase.

8. The rotary electric machine apparatus according to claim 1 ,
wherein the permanent magnets are embedded inside of the rotor, and
wherein when defining, as the current vector of most advanced phase, a current vector of current command values calculated by a maximum torque/current control on the dq-axis rotating coordinate system of most advanced phase, and
defining, as the current vector of middle phase, a current vector of current command values calculated by the maximum torque/current control on the dq-axis rotating coordinate system of middle phase,
the current controller brings the controlling current vector close to the current vector of most advanced phase from the current vector of middle phase, as the winding currents increase.

9. The rotary electric machine apparatus according to claim 1 ,
wherein when, in an execution region of a magnetic flux weakening control, defining, as the current vector of most advanced phase, a current vector of current command values calculated by the magnetic flux weakening control on the dq-axis rotating coordinate system of most advanced phase, and
defining, as the current vector of middle phase, a current vector of current command values calculated by the magnetic flux weakening control on the dq-axis rotating coordinate system of middle phase,
the current controller brings the controlling current vector close to the current vector of most advanced phase from the current vector of middle phase, as the winding currents increase.

10. The rotary electric machine apparatus according to claim 1 ,
wherein a pole number of the permanent magnets provided in the rotor is 8, and a slot number of the stator around which the plural-phase windings are wound is 1

Assignees

• Mitsubishi Electric Corp

Inventors

• Mori Tatsuya
• Kubo Kenta
• HIROTANI Yu

Classifications

• H02P27/06

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

• H02P6/10 Primary

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

• H02K21/12

  with stationary armatures and rotating magnets · CPC title

• H02K1/27

  Rotor cores with permanent magnets · CPC title

• B62D5/0403

  characterised by constructional features, e.g. common housing for motor and gear box · CPC title