Electrical system for pulse-width modulated control of a power inverter using phase-shifted carrier signals and related operating methods

• US 8,115,433 B2
• Filed: 09/23/2008
• Issued: 02/14/2012
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Welchko, Brian A.
• Primary Examiner(s): Benson, Walter
• Assistant Examiner(s): Luo, David S
• Application Number:
  US12/236,172
• Publication Number:
  US 20100072928A1
• Time in Patent Office: 1,239 Days
• Field of Search: 318/400.13, 318/400.11, 318/400.12, 318/807, 318/432
• US Class Current: 318/400.13
• CPC Class Codes: B60L 2210/46 with more than three phases
• CPC Class Codes: B60L 2220/58 with more than three phases
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02P 25/22 Multiple windings; Windings for more than three phases
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

Systems and methods are provided for pulse-width modulated control of power inverter using phase-shifted carrier signals. An electrical system comprises an energy source and a motor. The motor has a first set of windings and a second set of windings, which are electrically isolated from each other. An inverter module is coupled between the energy source and the motor and comprises a first set of phase legs coupled to the first set of windings and a second set of phase legs coupled to the second set of windings. A controller is coupled to the inverter module and is configured to achieve a desired power flow between the energy source and the motor by modulating the first set of phase legs using a first carrier signal and modulating the second set of phase legs using a second carrier signal. The second carrier signal is phase-shifted relative to the first carrier signal.

Claims

1. An electrical system for use in a vehicle, the electrical system comprising:

an energy source;

a motor having a first set of windings and a second set of windings, the first set of windings being electrically isolated from the second set of windings, and the motor including a stator having a plurality of slots, wherein;

the first set of windings comprises a first three-phase set of windings;

the second set of windings comprises a second three-phase set of windings; and

the first three-phase set of windings and the second three-phase set of windings have an identical winding structure, each phase winding of the second three-phase set of windings occupying slots of the plurality of slots that are occupied by its corresponding phase winding of the first three-phase set of windings;

an inverter module coupled between the energy source and the motor, the inverter module comprising;

a first set of phase legs coupled to the first set of windings; and

a second set of phase legs coupled to the second set of windings; and

a controller coupled to the inverter module, the controller being configured to achieve a desired power flow between the energy source and the motor by;

modulating the first set of phase legs using a first carrier signal; and

modulating the second set of phase legs using the second carrier signal, the second carrier signal being phase-shifted relative to the first carrier signal.

2. The electrical system of claim 1, further comprising a capacitor coupled to the inverter module and the energy source, wherein the capacitor is electrically parallel to the energy source.

3. The electrical system of claim 1, wherein the controller is configured to:

identify a modulation mode for the inverter module; and

determine the second carrier signal by adding a phase shift to the first carrier signal, wherein the phase shift is based on the modulation mode.

4. The electrical system of claim 3, wherein if the modulation mode is a continuous modulation mode, the controller is configured to determine the second carrier signal by adding a 90°

phase shift to the first carrier signal.

5. The electrical system of claim 3, wherein if the modulation mode is a discontinuous modulation mode, the controller is configured to determine the second carrier signal by adding a 180°

phase shift to the first carrier signal.

6. The electrical system of claim 1, wherein:

the first set of phase legs comprises three phase legs, each being connected to a respective phase of the first three-phase set of windings; and

the second set of phase legs comprises three phase legs, each being connected to a respective phase of the second three-phase set of windings.

7. The electrical system of claim 1, wherein each phase winding of the second three-phase set of windings has a winding factor corresponding to a winding factor of its corresponding phase winding of the first three-phase set of windings.

8. An automotive drive system comprising:

an energy source;

an electric motor comprising a first winding and a second winding, the first winding and the second winding being electrically isolated, wherein the first winding and the second winding each correspond to a first phase of the electric motor;

an inverter module coupled to the energy source, the inverter module comprising;

a first phase leg coupled to the first winding; and

a second phase leg coupled to the second winding; and

a controller coupled to the inverter module, the controller being configured to;

modulate the first phase leg using a first carrier;

identify a modulation mode for the inverter module;

determine a second carrier based on the modulation mode, the second carrier being phase-shifted relative to the first carrier; and

modulate the second phase leg using the second carrier.

9. The automotive drive system of claim 8, wherein the first winding and the second winding have the same winding structure.

10. The automotive drive system of claim 9, wherein the first winding and the second winding have the same winding factor and occupy the same slots in a stator of the electric motor.

11. The automotive drive system of claim 8, wherein if the modulation mode is a continuous modulation mode, the controller determines the second carrier by adding a 90°

phase shift to the first carrier.

12. The automotive drive system of claim 8, wherein if the modulation mode is a discontinuous modulation mode, the controller determines the second carrier by adding a 180°

phase shift to the first carrier.

13. The automotive drive system of claim 8, wherein:

the electric motor further comprises a third winding and a fourth winding, the third winding and the fourth winding being electrically isolated;

the third winding and the fourth winding each correspond to a second phase of the electric motor;

the inverter module further comprises;

a third phase leg coupled to the third winding; and

a fourth phase leg coupled to the fourth winding; and

the controller is configured to;

modulate the third phase leg using the first carrier; and

modulate the fourth phase leg using the second carrier.

14. The automotive drive system of claim 13, wherein:

the electric motor further comprises a fifth winding and a sixth winding, the fifth winding and the sixth winding being electrically isolated;

the fifth winding and the sixth winding each correspond to a third phase of the electric motor;

the inverter module further comprises;

a fifth phase leg coupled to the fifth winding; and

a sixth phase leg coupled to the sixth winding; and

the controller is configured to;

modulate the fifth phase leg using the first carrier; and

modulate the sixth phase leg using the second carrier.

15. The automotive drive system of claim 8, further comprising a capacitor coupled to the inverter module and the energy source, wherein the capacitor is electrically parallel to the energy source.

16. The automotive drive system of claim 8, wherein the energy source is selected from the group consisting of a battery, a fuel cell, an ultracapacitor, a generator output.

17. A method for operating an inverter module for an electric motor, the electric motor having a first set of windings coupled to a first set of phase legs of the inverter module and a second set of windings coupled to a second set of phase legs of the inverter module, the method comprising:

modulating the first set of phase legs using a first carrier signal;

identifying a modulation mode for the inverter module;

determining a second carrier signal based on the modulation mode, the second carrier signal having a phase shift relative to the first carrier signal; and

modulating the second set of phase legs using the second carrier signal.

18. The method of claim 17, wherein determining the second carrier signal comprises adding a 90°

phase shift to the first carrier signal if the modulation mode is a continuous modulation mode.

19. The method of claim 17, wherein determining the second carrier signal comprises adding a 180°

phase shift to the first carrier signal if the modulation mode is a discontinuous modulation mode.

20. An electrical system for use in a vehicle, the electrical system comprising:

an energy source;

a motor having a first set of windings and a second set of windings, the first set of windings being electrically isolated from the second set of windings;

an inverter module coupled between the energy source and the motor, the inverter module comprising;

a first set of phase legs coupled to the first set of windings; and

a second set of phase legs coupled to the second set of windings; and

a controller coupled to the inverter module, the controller being configured to achieve a desired power flow between the energy source and the motor by;

modulating the first set of phase legs using a first carrier signal;

identifying a modulation mode for the inverter module;

determining a second carrier signal by adding a phase shift to the first carrier signal, wherein the phase shift is based on the modulation mode; and

modulating the second set of phase legs using the second carrier signal.