CHARGING ENERGY SOURCES WITH A RECTIFIER USING DOUBLE-ENDED INVERTER SYSTEM

• US 20090033255A1
• Filed: 06/10/2008
• Published: 02/05/2009
• Est. Priority Date: 07/30/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: WELCHKO, Brian A., SMITH, Gregory S., NAGASHIMA, James M., PERISIC, Milun, JOHN, George, CHAKRABARTI, Sibaprasad
• Granted Patent: US 8,058,830 B2
• Time in Patent Office: Days
• US Class Current: 318/139
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Systems and methods are provided for charging energy sources with a rectifier using a double-ended inverter system. An apparatus is provided for an electric drive system for a vehicle. The electric drive system comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A first energy source is coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor. A second inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A rectifier is coupled to the second inverter and configured to produce a direct current output. The second inverter is configured to provide power from the rectifier to the electric motor.

Claims

1. An electric drive system for a vehicle comprising:

an electric motor configured to provide traction power to the vehicle;

a first inverter coupled to the electric motor, the first inverter being configured to provide alternating current to the electric motor;

a first energy source coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor;

a second inverter coupled to the electric motor, the second inverter being configured to provide alternating current to the electric motor; and

a rectifier coupled to the second inverter, the rectifier being configured to produce a direct current output;

wherein the second inverter being configured to provide power from the rectifier to the electric motor.

2. The electric drive system of claim 1, further comprising a controller coupled to the first inverter and the second inverter, the controller being configured to achieve a desired power flow between the first energy source, the rectifier, and the electric motor.

3. The electric drive system of claim 2, further comprising a generator coupled to the rectifier, the generator being configured to provide electrical energy to the rectifier.

4. The electric drive system of claim 3, further comprising an internal combustion engine coupled to the generator, the internal combustion engine being configured to provide mechanical energy to the generator, wherein the generator is configured to convert mechanical energy to electrical energy.

5. The electric drive system of claim 4, the first energy source having a state of charge, wherein the controller is coupled to the first energy source and is configured to:

monitor the state of charge of the first energy source; and

provide charging power to the first energy source from the rectifier if the state of charge is less than a threshold value.

6. The electric drive system of claim 5, wherein the controller is coupled to the internal combustion engine and is configured to start the internal combustion engine if the state of charge is less than the threshold value.

7. The electric drive system of claim 6, the internal combustion engine having a designated operating point corresponding to a peak energy efficiency, wherein the controller is configured to operate at the internal combustion engine at an operating point substantially near the designated operating point.

8. The electric drive system of claim 6, wherein the controller is configured to stop the internal combustion engine if the state of charge is greater than a second threshold value.

9. The electric drive system of claim 4, wherein the first energy source is a battery.

10. An automotive drive system comprising:

an electric motor configured to provide traction power;

a first inverter coupled to the electric motor, the first inverter being configured to provide alternating current to the electric motor;

a first energy source coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor;

a second inverter coupled to the electric motor, the second inverter being configured to provide alternating current to the electric motor;

a second energy source coupled to the second inverter, wherein the second inverter is configured to provide power flow between the second energy source and the electric motor; and

a rectifier coupled between the first energy source and the first inverter, such that the rectifier and the first energy source are electrically parallel, wherein the rectifier is configured to produce a direct current output.

11. The automotive drive system of claim 10, further comprising a controller coupled to the first inverter and the second inverter, the controller being configured to achieve a desired power flow between the first energy source, the second energy source, the rectifier, and the electric motor.

12. The automotive drive system of claim 11, wherein the second energy source is an ultracapacitor.

13. The automotive drive system of claim 11, further comprising a generator coupled to the rectifier, the generator being configured to provide electrical energy to the rectifier.

14. The automotive drive system of claim 13, further comprising an internal combustion engine coupled to the generator, the internal combustion engine being configured to provide mechanical energy to the generator, wherein the generator is configured to convert mechanical energy to electrical energy.

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

the first energy source is a battery having a state of charge, and

the controller is coupled to the first energy source and the internal combustion engine, and is configured to;

monitor the state of charge;

start the internal combustion engine if the state of charge is less than a threshold value; and

provide charging power to the first energy source from the internal combustion engine.

16. A method for controlling an electric motor using a double-ended inverter system coupled to a first energy source and a rectifier, the first energy source having a state of charge, wherein the rectifier is coupled to a generator which is coupled to an internal combustion engine, the method comprising:

modulating the double-ended inverter system to provide power to the electric motor from the first energy source;

monitoring the state of charge of the first energy source; and

if the state of charge is less than a threshold value, providing power to the double-ended inverter system from the internal combustion engine through the generator.

17. The method of claim 16, wherein providing power to the double-ended inverter system from the internal combustion engine further comprises starting the internal combustion engine.

18. The method of claim 16, further comprising modulating the double-ended inverter system to provide power to the electric motor from the rectifier.

19. The method of claim 16, further comprising modulating the double-ended inverter system to charge the first energy source from the rectifier.

20. The method of claim 19, further comprising stopping the internal combustion engine if the state of charge is greater than a second threshold value.