Granted Patent B2

US 8,115,433 · App. 12/236,172 · Granted Feb 14, 2012

Abstract

Claims (75)

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.

Assignments (13)