Soft hybrid-electric vehicle power supply circuit

• US 7,030,511 B2
• Filed: 04/09/2002
• Issued: 04/18/2006
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Zarei, Shahram
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US10/063,290
• Publication Number:
  US 20030191576A1
• Time in Patent Office: 1,470 Days
• Field of Search: 290/40.C
• US Class Current: 307/39
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A soft hybrid-electric vehicle power supply circuit (14) is provided. The circuit includes a load sensor (19), which generates a load signal. A high-voltage bus (26) supplies a high voltage for a high-voltage load (30) and a low-voltage bus (28) is electrically coupled to and supplying a low-voltage to a low-voltage load (32). A converter circuit (24) is electrically coupled to the high-voltage bus (26), the low-voltage bus (28), and a high-voltage load (30). The converter circuit (24) maintains a predetermined minimum voltage level on the high-voltage load (30) by switching between the high-voltage bus (26) and the low-voltage bus (28) in response to the load signal. A method of maintaining the predetermined minimum voltage level is also provided.

Claims

1. A soft hybrid-electric vehicle power supply circuit for a soft hybrid-electric vehicle comprising:

a load sensor generating a load signal;

a high-voltage bus supplying a high voltage for a high-voltage load;

a low-voltage bus electrically coupled to and supplying a low-voltage to a low-voltage load; and

a converter circuit electrically coupled to said high-voltage bus, said low-voltage bus, and said high voltage load, said converter circuit maintaining a predetermined minimum voltage level on said high-voltage load by switching between said high-voltage bus and said low-voltage bus in response to said load signal to supply power to said high-voltage load from only one of said high-voltage bus and said low-voltage bus.

2. A circuit as in claim 1 further comprising an integrated starter generator supplying power to said high-voltage bus or an engine.

3. A circuit as in claim 2 further comprising:

an integrated starter generator control circuit electrically coupled to said integrated starter generator and said high-voltage bus, said integrated starter generator control circuit signaling said integrated starter generator in response to said load signal.

4. A circuit as in claim 3 wherein said integrated starter generator control circuit comprises:

an inverter processing electrical power between said high-voltage bus and said integrated starter generator; and

an integrated starter generator controller electrically coupled to said inverter and determining when to process said electrical power.

5. A circuit as in claim 1 wherein said converter circuit comprises:

a bi-directional switch; and

a bi-directional converter electrically coupled to said bi-directional switch and controlling said bi-directional switch, said bi-directional converter controlling direction of voltage conversion from either said high-voltage bus to said low-voltage bus or from said low-voltage bus to said high-voltage bus to maintain said predetermined minimum voltage level on said high-voltage load.

6. A circuit as in claim 1 further comprising a high-voltage energy storage device electrically coupled to and supplying power to said high-voltage bus.

7. A circuit as in claim 1 further comprising a low-voltage energy storage device electrically coupled to and supplying power to said low-voltage bus.

8. A circuit as in claim 1 wherein said converter circuit maintains said predetermined minimum voltage level during soft hybrid-electric vehicle engine high-loading periods.

9. A circuit as in claim 1 wherein said predetermined minimum voltage level is approximately 30 volts.

10. A soft hybrid-electric vehicle power supply system for a soft hybrid-electric vehicle comprising:

a engine propelling the soft hybrid electric vehicle;

an engine controller determining the status of said engine and generating a load signal; and

a soft hybrid-electric vehicle power supply circuit comprising;

a high-voltage bus supplying a high voltage for a high-voltage load;

a low-voltage bus electrically coupled to and supplying a low-voltage to a low-voltage load; and

a converter circuit electrically coupled to said high-voltage bus, said low-voltage bus, and said high voltage load, said converter circuit maintaining a predetermined minimum voltage level on said high-voltage load by switching between said high-voltage bus and said low-voltage bus in response to said load signal;

said converter circuit generating a converter circuit status signal upon switching voltage supply for said high-voltage load;

said engine controller signaling said engine to draw power from said high-voltage bus in response to said converter circuit status signal.

11. A system as in claim 10 further comprising an integrated starter generator supplying power to said high-voltage bus or said engine.

12. A system as in claim 11 further comprising an integrated starter generator control circuit electrically coupled to said integrated starter generator and said high-voltage bus, said integrated starter generator control circuit adjusting performance of said integrated starter generator.

13. A system as in claim 12 wherein said integrated starter generator control circuit comprises:

an inverter processing electrical power between said high-voltage bus and said integrated starter generator; and

an integrated starter generator controller electrically coupled to said inverter and determining when to process said electrical power.

14. A system as in claim 10 wherein said converter circuit comprises:

a bi-directional switch; and

a bi-directional converter electrically coupled to said bi-directional switch and controlling said bi-directional switch, said bi-directional converter controlling direction of voltage conversion from either said high-voltage bus to said low-voltage bus or from said low-voltage bus to said high-voltage bus to maintain said predetermined minimum voltage level on said high-voltage load.

15. A system as in claim 10 further comprising a high-voltage energy storage device electrically coupled to and supplying power to said high-voltage bus.

16. A system as in claim 10 further comprising a low-voltage energy storage device electrically coupled to and supplying power to said low-voltage bus.

17. A system as in claim 10 wherein said converter circuit maintains said predetermined minimum voltage level during soft hybrid-electric vehicle engine high-loading periods.

18. A system as in claim 10 wherein said predetermined minimum voltage level is approximately 30 volts.

19. A method of maintaining a predetermined minimum voltage level on a high-voltage load for a soft hybrid-electric vehicle comprising:

generating a load signal;

performing a high-voltage mode when said load signal is greater than a predetermined load and generating a first direction signal and performing a low-voltage mode when said load signal is less than or equal to a predetermined load and generating a second direction signal;

switching a bi-directional switch to an open state in response to said first direction signal and to a closed state in response to said second direction signal; and

performing an up-conversion in response to said first direction signal and a down-conversion in response to said second direction signal to maintain a predetermined minimum voltage level on the high-voltage load.

20. A method as in claim 19 wherein performing an up-conversion and a down-conversion comprises:

determining time to perform a voltage conversion;

determining a power rating for said voltage conversion; and

determining a duration of time to perform said voltage conversion.

21. A method as in claim 20 wherein switching said bi-directional switch and performing said voltage conversion comprises:

decoupling a high-voltage load from said high-voltage bus and coupling said high-voltage load to a low-voltage bus during soft hybrid-electric vehicle engine high-loading periods; and

coupling said high-voltage load to said high-voltage bus and decoupling said high-voltage load from said low-voltage bus during normal-loading periods.

22. A method as in claim 19 further comprising initiating a high-loading mode on a converting circuit before executing said high-loading made on an integrated starter generator.