Pole-number-changing rotary electric machine and driving method for pole-number-changing rotary electric machine

Patent metadata

Field	Value
Publication number	US-10312846-B2
Application number	US-201615537508-A
Country	US
Kind code	B2
Filing date	Jan 14, 2016
Priority date	Jan 16, 2015
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A pole-number-changing rotary electric machine includes: a rotary electric machine; an n-group inverter; and a control unit for controlling the n-group inverter, wherein the control unit controls current phases of a current flowing through stator coils such that a current phase degree of freedom, which is a number of current phases per pole pair controllable by the n-group inverter, is equal to a number of groups n×a number of phases m/2 at a time of high polarity driving and the number of groups n×the number of phases m at a time of low polarity driving, where the number of groups n is a multiple of 4 and the number of phases m is a natural number of 3 or more and relatively prime to the number of groups n.

First claim

The invention claimed is:

1. A pole-number-changing rotary electric machine comprising:
a rotary electric machine provided with a stator in which stator slots are arranged at regular intervals in a mechanical angle direction and a rotor rotated by magnetomotive forces generated by a current flowing through stator coils housed in the stator slots;
an n-group inverter for supplying an m-phase current to the stator coils; and
a controller for controlling the n-group inverter,
each of the magnetomotive forces corresponding to the stator slots being arranged at regular intervals, and a number of poles in the pole-number-changing rotary electric machine being changed between a first number of poles and a second number of poles, wherein the second number of poles is smaller than the first number of poles, wherein
the controller controls current phases of the current flowing through the stator coils such that a current phase degree of freedom, which is a number of current phases used in stator slots that correspond to one pole pair controllable by the n-group inverter, is equal to a number of groups n×a number of phases m/2 at a time of a first polarity driving corresponding to the first number of poles and is equal to a number of groups n×the number of phases m at a time of a second polarity driving corresponding to the second number of poles, where the number of groups n is 4 or a multiple of 4 and the number of phases m is 3 or a natural number greater than 3 and m and n are prime numbers relative to each other.

2. The pole-number-changing rotary electric machine according to claim 1 , wherein
the controller controls current phases of a current flowing through the stator coils such that a number of poles at the time of the first polarity driving is twice a number of poles at the time of the second polarity driving, and
a number of different current phases used in the stator slots that corresponds to one pole pair is equal to a number of groups n×a number of phases m/2 at the time of the first polarity driving and the number of groups n×the number of phases m at the time of the second polarity driving.

3. The pole-number-changing rotary electric machine according to claim 1 , wherein
the controller controls current phases of a current flowing through the stator coils such that a number of poles at the time of the first polarity driving is twice a number of poles at the time of the second polarity driving, and
a number of different current phases used in the stator slots that corresponds to one pole pair is the same at the time of the first polarity driving and at the time of the second polarity driving and equal to a number of groups n×a number of phases m/2.

4. The pole-number-changing rotary electric machine according to claim 1 , wherein
when a number of stator slots of the stator slots is set to n s , n s /(a number of groups n×a number of phases m) is a natural number.

5. The pole-number-changing rotary electric machine according to claim 4 , wherein
the number of groups is n=4 and the number of phases is m=3.

6. The pole-number-changing rotary electric machine according to claim 4 , wherein
the number of groups is n=4 and the number of phases is m=5.

7. The pole-number-changing rotary electric machine according to claim 4 , wherein
the number of groups is n=8 and the number of phases is m=3.

8. The pole-number-changing rotary electric machine according to claim 1 , wherein
the rotary electric machine is an induction machine.

9. A driving method for a pole-number-changing rotary electric machine including a rotary electric machine provided with a stator in which stator slots are arranged at regular intervals in a mechanical angle direction and a rotor rotated by magnetomotive forces generated by a current flowing through stator coils housed in the stator slots, the driving method comprising:
supplying, by an n-group inverter, an m-phase current to the stator coils; and
controlling, by circuitry, the n-group inverter,
each of the magnetomotive forces corresponding to the stator slots being arranged at regular intervals, and a number of poles in the pole-number-changing rotary electric machine being changed between a first number of poles and a second number of poles, wherein the second number of poles is smaller than the first number of poles; and
performing, by the circuitry, current supply in which an m-phase current is supplied to the stator coils by the n-group inverter, and in the current supply:
at the time of a polarity driving corresponding to the second number, current phases of the current flowing through the stator coils are controlled such that a current phase degree of freedom, which is a number of current phases used in stator slots that correspond to one pole pair controllable by the n-group inverter, is equal to a number of groups n×a number of phases m, where the number of groups n is 4 or a multiple of 4 and the number of phases m is 3 or a natural number greater than 3 and m and n are prime numbers relative to each other, and
at the time of a polarity driving corresponding to the first number, the current phases of the current flowing into the stator coils are changed such that the current phase degree of freedom is equal to the number of groups n×the number of phases m/2.

10. A pole-number-changing rotary electric machine comprising:
a rotary electric machine provided with a stator in which stator slots are arranged at regular intervals in a mechanical angle direction and a rotor rotated by magnetomotive forces generated by a current flowing through stator coils housed in the stator slots;
an n-group inverter configured to supply an m-phase current to the stator coils; and
circuitry configured to control the n-group inverter,
each of the magnetomotive forces corresponding to the stator slots being arranged at regular intervals, and a number of poles in the pole-number-changing rotary electric machine being changed between a first number of poles and a second number of poles, wherein the second number of poles is smaller than the first number of poles, wherein
the circuitry controls current phases of the current flowing through the stator coils such that a current phase degree of freedom, which is a number of current phases used in stator slots that correspond to one pole pair controllable by the n-group inverter, is equal to a number of groups n×a number of phases m/2 at a time of a polarity driving corresponding to the first number and is equal to a number of groups n×the number of phases m at a time of a polarity driving corresponding to the second number, where the number of groups n is 4 or a multiple of 4 and the number of phases m is 3 or a natural number greater than 3 and m and n are prime numbers relative to each other.

Assignees

• Mitsubishi Electric Corp

Inventors

• Hidaka Yuki
• Komatsu Taiga
• Arita Hideaki
• Daikoku Akihiro
• Hazeyama Moriyuki

Classifications

• H02P25/22

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

• H02K3/28

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title

• H02K3/522

  for generally annular cores with salient poles · CPC title

• H02K3/12

  arranged in slots · CPC title

• H02K3/51

  applicable to rotors only · CPC title