Method and apparatus for a fuel cell propulsion system

• US 6,321,145 B1
• Filed: 01/29/2001
• Issued: 11/20/2001
• Est. Priority Date: 01/29/2001
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Rajashekara, Kaushik
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/771,532
• Time in Patent Office: 295 Days
• Field of Search: 701/22, 290/9, 290/10, 290/13, 290/18, 290/22, 290/26, 290/31, 363/65, 429/22, 429/23, 429/24, 429/12, 429/9, 322/19, 322/28, 322/26, 322/45, 180/65.3, 180/165, 180/65.2, 180/65.1, 180/65.4
• US Class Current: 701/22
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y10S 429/90 Fuel cell including means for power conditioning, e.g. Conversion to ac

Abstract

Propulsion control system and method are provided for use in vehicles including a propulsion motor that is powered by a fuel cell. The fuel cell unit produces a compatible voltage for the propulsion motor, thereby removing the need for a dc/dc boost converter. A buck/boost converter and a standard 12 volt battery are used to start the fuel cell. An inverter receives dc electric voltage from the fuel cell and outputs ac electric voltage to the propulsion motor. A vehicle controller receives a voltage input from the fuel cell unit and outputs a current reference to a comparing device. The comparing device compares the current reference from the vehicle controller to an actual current of the fuel cell unit and then outputs a signal to a PI control which outputs a control signal to a fuel cell controller, whereby the power output of the fuel cell is controlled based on the actual current of the fuel cell.

Claims

1. A propulsion control system adapted for use in a fuel cell powered vehicle, said system comprising:

a propulsion motor;

a fuel cell unit outputting dc electric voltage;

a power battery outputting dc power battery voltage;

a dc/dc boost converter receiving said dc electric voltage from said fuel cell unit, said dc/dc boost converter outputting boosted dc electric voltage;

an inverter receiving said dc power battery voltage from said power battery and said boosted dc electric voltage from said dc/dc boost converter, said inverter outputting ac electric voltage to said propulsion motor;

a vehicle controller receiving at least one electrical measurement input from said power battery, said vehicle controller outputting an electrical measurement reference; and

a comparing device receiving said electrical measurement reference from said vehicle controller, said comparing device receiving an actual electrical measurement from said fuel cell, said comparing device outputting a signal to said dc/dc boost converter, whereby the power output of said fuel cell remains constant.

2. The propulsion control system for fuel cell powered vehicles as described in claim 1, further comprising:

a PI control receiving said signal of said comparing device, said PI control outputting a control signal; and

a PWM logic controller receiving said control signal of said PI control, said PWM logic controller outputting a gate control signal to said dc/dc boost converter.

3. A propulsion control system adapted for use in a fuel cell powered vehicle, said system comprising:

a propulsion motor;

a fuel cell unit outputting dc electric voltage;

a power battery outputting dc power battery voltage, said power battery and said fuel cell unit being characteristically matched;

a fuel cell controller connected to said fuel cell unit;

an inverter receiving said dc power battery voltage from said power battery and said dc electric voltage from said fuel cell unit, said inverter outputting ac electric voltage to said propulsion motor;

a vehicle controller receiving a voltage input from said dc battery voltage, said vehicle controller outputting a current reference;

a comparing device receiving said current reference from said vehicle controller, said comparing device receiving an actual current from said fuel cell unit, said comparing device outputting a signal; and

a PI control receiving said signal of said comparing device, said PI control outputting a control signal to said fuel cell controller, whereby the power output of said fuel cell is controlled.

4. The propulsion control system for fuel cell powered vehicles as described in claim 3, further comprising a gas flow calculating means for calculating a required gas flow to said fuel cell unit for controlling the power output of said fuel cell unit.

5. The propulsion control system for fuel cell powered vehicles as described in claim 4, wherein the output power of said fuel cell unit being regulated by controlling a flow of hydrogen inputted into said fuel cell unit.

6. A propulsion control system adapted for use in a fuel cell powered vehicle, said system comprising:

a propulsion motor;

a fuel cell unit outputting dc electric voltage;

a standard 12 volt battery outputting dc battery voltage;

a dc/dc boost converter receiving said dc electric voltage from said fuel cell unit, said dc/dc boost converter outputting boosted dc electric voltage;

a buck/boost converter receiving said dc battery voltage from said standard 12 volt battery, said buck/boost converter outputting buck boosted dc electric voltage, said buck boosted dc electric voltage from said buck/boost converter starting said fuel cell;

an inverter receiving said boosted dc electric voltage from said dc/dc boost converter, said inverter outputting ac electric voltage to said propulsion motor;

a vehicle controller outputting a current reference and a voltage reference;

a first comparing device receiving said current reference from said vehicle controller, said first comparing device receiving an actual current from said fuel cell unit, said first comparing device outputting a first signal;

a first PI control receiving said first signal of said first comparing device, said first PI control outputting a first control signal;

a fuel cell controller receiving said first control signal of said first PI control;

a second comparing device receiving said voltage reference from said vehicle controller, said second comparing device receiving an actual voltage of said boosted dc electric voltage of said dc/dc boost converter, said second comparing device outputting a second signal;

a second PI control receiving said second signal of said second comparing device, said second PI control outputting a second control signal; and

a PWM logic controller receiving said second control signal from said second PI control, said PWM logic controller outputting a gate control signal to said dc/dc boost converter, whereby the power output of said fuel cell is maintained at a constant level.

7. The propulsion control system for fuel cell powered vehicles as described in claim 6, further comprising a buffer tank of hydrogen.

8. The propulsion control system for fuel cell powered vehicles as described in claim 6, further comprising a gas flow calculating means for calculating a required gas flow to said fuel cell unit for controlling the power output of said fuel cell unit.

9. The propulsion control system for fuel cell powered vehicles as described in claim 8, wherein the output power of said fuel cell unit being regulated by controlling a flow of hydrogen inputted into said fuel cell unit.

10. A propulsion control system adapted for use in a fuel cell powered vehicle, said system comprising:

a propulsion motor;

a fuel cell unit outputting a compatible dc voltage for said propulsion motor;

a standard 12 volt battery outputting dc battery voltage;

a buck/boost converter receiving said dc battery voltage from said standard 12 volt battery, said buck/boost converter outputting buck boosted dc electric voltage, said buck boosted dc electric voltage from said buck/boost converter starting said fuel cell;

an inverter receiving said compatible dc voltage from said fuel cell unit, said inverter outputting ac electric voltage to said propulsion motor;

a vehicle controller receiving a voltage input from said compatible dc voltage of said fuel cell unit, said vehicle controller outputting a current reference;

a comparing device receiving said current reference from said vehicle controller and receiving an actual current from said fuel cell unit, said comparing device outputting a signal;

a PI control receiving said signal of said comparing device, said PI control outputting a control signal; and

a fuel cell controller receiving said control signal of said PI control, whereby the power output of said fuel cell is controlled.

11. The propulsion control system for fuel cell powered vehicles as described in claim 10, further comprising a buffer tank of hydrogen.

12. The propulsion control system for fuel cell powered vehicles as described in claim 10, further comprising a gas flow calculating means for calculating a required gas flow to said fuel cell stack for controlling the power output of said fuel cell unit.

13. The propulsion control system for fuel cell powered vehicles as described in claim 12, wherein the output power of said fuel cell unit being regulated by controlling a flow of hydrogen inputted into said fuel cell unit.

14. A propulsion control method adapted for use in a fuel cell powered vehicle, said method comprising:

providing a power battery that outputs dc power battery voltage;

providing a fuel cell unit that outputs dc electric voltage;

boosting said dc electric voltage through a dc/dc boost converter;

inverting said power battery voltage and said boosted dc electric voltage into ac voltage through an inverter;

propelling the vehicle through a propulsion motor that receives ac voltage from said inverter;

providing a vehicle controller which receives at least one electrical measurement from said power battery;

providing a comparing device which receives an electrical measurement reference from said vehicle controller; and

outputting a signal from said comparing device to said dc/dc boost converter, whereby the power output of said fuel cell remains constant.

15. The method according to claim 14, wherein said outputted signal from said comparing device further comprising the steps of:

receiving said signal of said comparing device into a PI control;

outputting a control signal from said PI control to a PWM logic controller; and

outputting a gate control signal from said PWM logic controller to said dc/dc boost converter.

16. A propulsion control method adapted for use in a fuel cell powered vehicle, said method comprising:

providing dc electric voltage through a power battery and a fuel cell unit, said power battery and said fuel cell unit being characteristically matched;

outputting a voltage input from said dc electric voltage to a vehicle controller, said vehicle controller outputting a current reference;

inverting said dc electric voltage from said power battery and said fuel cell unit into ac voltage through an inverter;

propelling the vehicle through a propulsion motor that receives ac voltage from said inverter;

comparing said current reference from said vehicle controller with an actual current of said fuel cell unit through a comparing device;

outputting a signal to a PI control from said comparing device; and

outputting a control signal to a fuel cell controller from said PI control, said fuel cell controller being connected to said fuel cell unit, thereby controlling the power output of said fuel cell.

17. The method according to claim 16, further comprising the steps of calculating a required gas flow to said fuel cell unit to control the power output of said fuel cell unit through a gas flow calculating means.

18. The method according to claim 17, further comprising the steps of regulating the output power of said fuel cell unit by controlling a flow of hydrogen inputted into said fuel cell unit.

19. A propulsion control method adapted for use in a fuel cell powered vehicle, said method comprising:

providing a standard 12 volt battery that outputs dc battery voltage;

providing a fuel cell unit that outputs dc electric voltage;

boosting said dc electric voltage from said fuel cell unit through a dc/dc boost converter;

boosting said dc battery voltage from said standard 12 volt battery through a buck/boost converter;

starting said fuel cell through said boosted dc battery voltage from said standard 12 volt battery;

inverting said boosted dc electric voltage from said fuel cell unit into ac electric voltage through an inverter;

propelling the electric vehicle through a propulsion motor that receives ac voltage from said inverter;

outputting a current reference and a voltage reference from a vehicle controller;

comparing said current reference from said vehicle controller with an actual current of said fuel cell unit through a first comparing device;

outputting a first signal from said first comparing device;

inputting said first signal from said first comparing device into a first PI control;

outputting a first control signal from said first PI control into a fuel cell controller;

comparing said voltage reference from said vehicle controller with an actual voltage of said dc/dc boost converter through a second comparing device;

outputting a second signal from said second comparing device to a second PI control; and

outputting a second control signal to a PWM logic controller from said second PI control, whereby the power output of said fuel cell is maintained at a constant level.

20. The method according to claim 19, further comprising the steps of supplying additional hydrogen to said fuel cell through a buffer tank of hydrogen.

21. The method according to claim 19, further comprising the steps of calculating a required gas flow to said fuel cell unit to control the power output of said fuel cell unit through a gas flow calculating means.

22. The method according to claim 21, further comprising the steps of regulating the output power of said fuel cell unit by controlling a flow of hydrogen inputted into said fuel cell unit.

23. A propulsion control method adapted for use in a fuel cell powered vehicle, said method comprising:

providing dc electric voltage through a fuel cell unit, said fuel cell unit producing a compatible voltage;

providing a standard 12 volt battery that outputs dc battery voltage;

boosting said dc battery voltage from said standard 12 volt battery through a buck/boost converter;

starting said fuel cell through said boosted dc battery voltage from said standard 12 volt battery;

inverting said dc electric voltage from said fuel cell unit into ac electric voltage through an inverter;

propelling the vehicle through a propulsion motor that receives ac voltage from said inverter;

outputting a current reference from a vehicle controller;

inputting a voltage reference into said vehicle controller from said fuel cell unit;

comparing said current reference from said vehicle controller with an actual current of said fuel cell unit through a comparing device;

outputting a signal to a PI control from said comparing device; and

outputting a control signal to a fuel cell controller from said PI control, said fuel cell controller being connected to said fuel cell unit, whereby the power output of said fuel cell is controlled.

24. The method according to claim 23, further comprising the steps of supplying additional hydrogen to said fuel cell through a buffer tank of hydrogen.

25. The method according to claim 23, further comprising the steps of calculating a required gas flow to said fuel cell unit to control the power output of said fuel cell unit through a gas flow calculating means.

26. The method according to claim 25, further comprising the steps of regulating the output power of said fuel cell unit by controlling a flow of hydrogen inputted into said fuel cell unit.