PRECHARGING A HIGH-VOLTAGE BUS USING A VOLTAGE-REGULATED POWER SUPPLY

• US 20100001582A1
• Filed: 07/01/2008
• Published: 01/07/2010
• Est. Priority Date: 07/01/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: NASSAR, Jason A., NEWHOUSE, Vernon L., WOLAK, Jeffrey T.
• Granted Patent: US 8,049,372 B2
• Time in Patent Office: Days
• US Class Current: 307/10.1
• CPC Class Codes: B60L 2270/20 Inrush current reduction, i.e. avoiding high currents when connecting the battery
• CPC Class Codes: B60L 3/00 Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption methods or circuit arrangements for monitoring or controlling batteries or fuel cells B60L58/00
• CPC Class Codes: B60L 50/50 using propulsion power supplied by batteries or fuel cells
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Systems and methods are provided for precharging high-voltage buses. The precharge system comprises an energy source having a first terminal and a second terminal, wherein a first voltage is equal to a potential difference between the first terminal and the second terminal. The precharge system further comprises a bus having a first rail and a second rail, wherein a second voltage is equal to a potential difference between the first rail and the second rail. A first contactor is coupled between the first terminal and the first rail and a second contactor is coupled between the second terminal and the second rail. A controller is coupled to the energy source, the bus, and the contactors. The controller is configured to activate the second contactor, and thereafter activate the first contactor if the magnitude of a difference between the first voltage and the second voltage is less than a threshold tolerance.

Claims

1. A precharge system for use in a vehicle, the precharge system comprising:

a first energy source having a first terminal and a second terminal, wherein the first energy source has a first voltage equal to a potential difference between the first terminal and the second terminal;

a bus having a first rail and a second rail, wherein the bus has a second voltage equal to a potential difference between the first rail and the second rail;

a first contactor coupled between the first terminal and the first rail;

a second contactor coupled between the second terminal and the second rail; and

a controller coupled to the first energy source, the bus, the first contactor, and the second contactor, the controller being configured to;

activate the second contactor; and

thereafter activate the first contactor if the magnitude of a difference between the first voltage and the second voltage is less than a threshold tolerance.

2. The precharge system of claim 1 further comprising a power supply coupled to the bus, the power supply being configured to regulate the second voltage.

3. The precharge system of claim 2, wherein:

the controller is coupled to the power supply;

the controller is configured to provide an operative voltage command to the power supply; and

the power supply is configured to regulate the second voltage in response to the operative voltage command.

4. The precharge system of claim 2, further comprising an electrical load coupled to the bus, such that the electrical load and the power supply are electrically parallel.

5. The precharge system of claim 4, wherein the electrical load is a control circuit.

6. The precharge system of claim 4, wherein the electrical load is a vehicle power module.

7. The precharge system of claim 2, wherein the power supply is a battery charger.

8. The precharge system of claim 2, further comprising a second energy source, wherein the power supply is a DC-to-DC converter coupled to the second energy source.

9. The precharge system of claim 1, wherein the first energy source is selected from a group consisting of a battery pack, a fuel cell, and an ultracapacitor.

10. The precharge system of claim 1, wherein the first voltage is greater than or equal to 60 volts DC.

11. The precharge system of claim 1, wherein the bus is coupled to a vehicle charging station.

12. A method for precharging a bus coupled to a power supply configured to regulate the voltage of the bus, the bus being coupled to a set of contactors, wherein the set of contactors is coupled to an energy source, the method comprising:

commanding the power supply to a voltage level equal to the voltage of the energy source; and

thereafter activating the set of contactors if the magnitude of a difference between the voltage of the bus and the voltage of the energy source is less than a threshold tolerance.

13. The method of claim 12, wherein the set of contactors comprises a first contactor and a second contactor, the first contactor being coupled in series between a positive rail of the bus and a positive terminal of the energy source, and the second contactor being coupled in series between a negative rail of the bus and a negative terminal of the energy source, wherein activating the set of contactors further comprises:

activating the second contactor; and

activating the first contactor if the magnitude of a difference between the voltage of the bus and the voltage of the energy source is less than the threshold tolerance.

14. The method of claim 12, wherein an electrical load is coupled to the bus such that the electrical load and the power supply are electrically parallel, wherein the method further comprises decoupling the electrical load from the bus in response to activating the set of contactors.

15. The method of claim 12, wherein an electrical load is coupled to the bus such that the electrical load and the power supply are electrically parallel, wherein the method further comprises decoupling the power supply from the bus in response to activating the set of contactors.

16. The method of claim 12 further comprising activating the set of contactors if the voltage of the bus is equal to the voltage of the energy source.

17. The method of claim 12, further comprising commanding the power supply to a reduced voltage level if the magnitude of the difference between the voltage of the bus and the voltage of the energy source is greater than the threshold tolerance.

18. A vehicle comprising:

a high-voltage battery pack having a first voltage;

a set of contactors coupled to the high-voltage battery pack;

a bus coupled to the set of contactors, the bus having a second voltage; and

a controller coupled to the high-voltage battery pack, the set of contactors, and the bus, the controller being configured to activate the set of contactors if the magnitude of a difference between the first voltage and the second voltage is less than a threshold tolerance.

19. The vehicle of claim 18, further comprising a battery charger coupled to the bus, wherein the controller is configured to command the battery charger to provide a voltage to the bus equal to the first voltage.

20. The vehicle of claim 18, wherein the bus is coupled to a vehicle charging station.