HIGH POWER-DENSITY, HIGH BACK EMF PERMANENT MAGNET MACHINE AND METHOD OF MAKING SAME

• US 20120126733A1
• Filed: 11/19/2010
• Published: 05/24/2012
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: EL-Refaie, Ayman Mohamed Fawzi, King, Robert Dean
• Granted Patent: US 9,780,716 B2
• Time in Patent Office: Days
• US Class Current: 318/400.26
• CPC Class Codes: B60K 2006/264 with outer rotor and inner stator
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2210/42 Voltage source inverters
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02P 25/024 controlled by supply frequency
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 6/14 Electronic commutators
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/906 Motor or generator
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An electric drive system includes a permanent magnet machine having a rotor and a stator and a power converter electrically coupled to the permanent magnet machine and configured to convert a DC link voltage to an AC output voltage to drive the permanent magnet machine. The power converter includes a plurality of silicon carbide switching devices having a voltage rating that exceeds a peak line-to-line back electromotive force of the permanent magnet machine at a maximum speed of the permanent magnet machine.

Claims

1. An electric drive system comprising:

a permanent magnet machine having a rotor and a stator; and

a power converter electrically coupled to the permanent magnet machine and configured to convert a DC link voltage to an AC output voltage to drive the permanent magnet machine, the power converter comprising;

a plurality of silicon carbide (SiC) switching devices having a voltage rating that exceeds a peak line-to-line back electromotive force (emf) of the permanent magnet machine at a maximum speed of the permanent magnet machine.

2. The electric drive system of claim 1 wherein the plurality of SiC switching devices comprise a plurality of SiC metal-oxide-semiconductor field effect transistors (MOSFETs).

3. The electric drive system of claim 1 wherein a maximum DC link voltage of the electric drive system is less than the voltage rating of the plurality of SiC MOSFETs.

4. The electric drive system of claim 3 wherein the plurality of SiC MOSFETs have a voltage rating greater than approximately three kV.

5. The electric drive system of claim 1 wherein the permanent magnet machine comprises a multi-phase permanent magnet traction motor comprising one of 3, 5, 7, and 9 phases.

6. The electric drive system of claim 1 wherein the permanent magnet machine comprises a single-phase permanent magnet traction motor.

7. The electric drive system of claim 1 wherein the permanent magnet machine comprises a multi-phase permanent magnet alternator coupled to a heat engine.

8. The electric drive system of claim 1 wherein the power converter further comprises plurality of diodes connected in an anti-parallel arrangement with the plurality of SiC MOSFETs.

9. The electric drive system of claim 1 wherein the power converter is a three-phase power converter.

10. A method of manufacturing an electric drive system comprising the steps of:

providing a silicon carbide (SiC) power converter having a plurality of SiC switching devices, the SiC power converter coupleable to a power source;

providing a permanent magnet machine having a peak line-to-line back electromotive force (emf) at maximum speed that is greater than a DC link voltage of the power source; and

coupling the SiC power converter to the permanent magnet machine to drive the permanent magnet machine.

11. The method of manufacturing of claim 10 wherein providing the SiC power converter comprises providing a SiC power converter having a plurality of metal-oxide-semiconductor field effect transistors (MOSFETs).

12. The method of manufacturing of claim 11 wherein providing the SiC power converter comprises providing a SiC power converter having a plurality of SiC MOSFETs.

13. The method of manufacturing of claim 12 comprising providing a SiC power converter having a plurality of SiC MOSFETs having a voltage rating that exceeds the DC link voltage during an uncontrolled generation mode of the permanent magnet machine.

14. A vehicle drive system comprising:

a motor comprising;

a permanent magnet rotor; and

a stator;

a DC link; and

a power converter electrically coupled between the DC link and the permanent magnet motor to drive the permanent magnet motor;

wherein the power converter comprises a plurality of silicon carbide (SiC) switching devices rated for a higher operating voltage than a maximum back electromotive force (emf) capable of being developed in the stator of the permanent magnet motor.

15. The vehicle drive system of claim 14 wherein the plurality of SiC switching devices comprise a plurality of SiC metal-oxide-semiconductor field effect transistors (MOSFETs).

16. The vehicle drive system of claim 14 wherein the plurality of SiC switching devices have a voltage rating of at least three kV.

17. The vehicle drive system of claim 14 wherein the power converter comprises a three-phase power converter.

18. The vehicle drive system of claim 14 further comprising a voltage source coupled to the DC link and configured to provide a source voltage to the DC link.

19. The vehicle drive system of claim 18 further comprising a controller electrically coupled to the power converter, the controller configured to detect a fault in the power converter when a peak line-to-line emf of the permanent magnet motor is within a threshold percentage of a voltage rating of the power source.

20. The vehicle drive system of claim 18 further comprising at least one contactor electrically coupled to the controller to receive signals therefrom, the at least one contactor connected between the power source and the power converter and configured to decouple the power source from the power converter upon receiving a fault signal from the controller.

21. The vehicle drive system of claim 18 wherein the voltage source comprises a DC source and a DC voltage converter configured to boost a voltage of the DC source to a DC link voltage.

22. The vehicle drive system of claim 21 wherein the DC source comprises at least one of a battery, an ultracapacitor, and a flywheel.

23. The vehicle drive system of claim 18 wherein the voltage source comprises an AC source and a rectifier configured to invert a voltage of the AC source to a DC link voltage.

24. The vehicle drive system of claim 14 wherein the permanent magnet motor comprises a multi-phase traction motor.

25. The vehicle drive system of claim 14 wherein the permanent magnet motor comprises a multi-phase permanent magnet alternator coupled to a heat engine of one of a Hybrid Electric Vehicle and a Plug-in Hybrid Electric Vehicle.