PLUG-IN HYBRID ELECTRIC VEHICLE

• US 20090321159A1
• Filed: 06/27/2008
• Published: 12/31/2009
• Est. Priority Date: 06/27/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Andri, Michael Jon
• Granted Patent: US 7,980,342 B2
• Time in Patent Office: Days
• US Class Current: 180/65.25
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• 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 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 20/18 for avoiding ageing of fuel
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/0677 Engine power
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A vehicle propulsion system and a method of its operation are described. As one example, the vehicle propulsion system includes a plug-in hybrid electric vehicle. The method may include: producing a motor output by selectively operating the motor to consume electrical energy stored on-board the vehicle; producing an engine output by selectively operating the engine to consume fuel stored on-board the vehicle; and increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor as a residence time of the fuel stored on-board the vehicle increases. The residence time of the fuel stored on-board the vehicle can provide an indication of fuel degradation, enabling the duty cycle of the engine to be selectively increased to enforce fuel use conditions, particularly in the context of a plug-in hybrid electric vehicle where fuel use may be less frequent.

Claims

1. A method of operating a vehicle propulsion system including a motor and an engine, the method comprising:

producing a motor output by selectively operating the motor to consume electrical energy stored on-board the vehicle;

producing an engine output by selectively operating the engine to consume fuel stored on-board the vehicle; and

increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor as a residence time of the fuel stored on-board the vehicle increases.

2. The method of claim 1, where the electrical energy is stored on-board the vehicle at an energy storage device;

and where the method further comprises;

periodically recharging the energy storage device by receiving electrical energy at the energy storage device from an energy source that is external the vehicle; and

where increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor includes adjusting a lower state of charge threshold of the energy storage device where the engine is activated to consume the fuel.

3. The method of claim 2, where adjusting the lower state of charge threshold of the energy storage device includes increasing the lower state of charge threshold as the residence time of the fuel increases.

4. The method of claim 1, where increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor includes reducing a vehicle operator request threshold where the engine is activated to consume the fuel.

5. The method of claim 1, where increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor includes increasing a duty cycle of the engine as the residence time of the fuel increases.

6. The method of claim 1, where increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor includes operating the engine to provide a greater contribution to the propulsion of the vehicle relative to the motor as residence time increases.

7. The method of claim 1, where the fuel is stored on-board the vehicle at a fuel tank;

and where the method further comprises;

periodically refueling the fuel tank by receiving fresh fuel at the fuel tank, and adjusting the residence time of the fuel stored on-board the vehicle responsive to the refueling the fuel tank.

8. The method of claim 7, where adjusting the residence time of the fuel stored on-board the vehicle includes reducing the residence time of the fuel responsive to the refueling the fuel tank.

9. The method of claim 8, where reducing the residence time of the fuel includes reducing the residence time responsive to a condition of the fresh fuel received at the fuel tank.

10. The method of claim 9, where the condition includes one or more of a quantity of the fresh fuel received at the fuel tank and a composition of the fresh fuel.

11. A vehicle propulsion system, comprising:

an electric battery configured to store electrical energy on-board the vehicle;

a fuel tank configured to store fuel on-board the vehicle;

an internal combustion engine configured to consume the fuel from the fuel tank to produce an engine output;

an electric motor configured to consume the electrical energy from the electric battery to produce a motor output; and

a control system configured to;

periodically recharge the electric battery by receiving electrical energy from an electrical energy source located external the vehicle;

discharge the energy storage device to operate the electric motor to produce the motor output;

selectively operate the engine according to a duty cycle to combust fuel stored on-board the vehicle to produce the engine output; and

increase the duty cycle of the engine as a residence time of the fuel stored on-board the vehicle increases.

12. The vehicle propulsion system of claim 11, where the controls system is further configured to reduce a duty cycle of the electric motor as the residence time of the fuel stored on-board the vehicle increases.

13. The vehicle propulsion system of claim 11, where the control system is configured to use the engine output to propel the vehicle or to use the engine output to recharge the electric battery.

14. The vehicle propulsion system of claim 11, further comprising an electric generator, where the control system is configured to use the engine output to power the electric motor via the electric generator.

15. The vehicle propulsion system of claim 11, further comprising an electric cable configured to electrically couple the electric battery to a power source residing external the vehicle;

and where the control system is configured to recharge the electric battery by controlling the electric battery to receive electrical energy from the power source when the power source is electrically coupled to the electric battery by the electric cable.

16. The vehicle propulsion system of claim 11, where the control system is configured to increase the duty cycle by increasing a lower state of charge threshold;

and where the control system is configured to operate the engine to consume the fuel when a state of charge of the electric battery is less than the lower state of charge threshold.

17. The vehicle propulsion system of claim 11, where the control system is configured to increase the duty cycle by reducing an operator request threshold;

and where the control system is configured to operate the engine to consume the fuel when an operator request received at the control system via an accelerator pedal exceeds the operator request threshold.

18. The vehicle propulsion system of claim 11, where the control system is configured to reduce the duty cycle of the engine responsive to a refueling of the fuel tank.

19. A method of operating a plug-in hybrid electric vehicle including an energy storage device, a motor, and an engine, the method comprising:

periodically recharging the energy storage device by receiving electrical energy at the energy storage device from a power source external the vehicle via an electrical energy transmission cable;

identifying degradation of a parameter of fuel stored on-board the vehicle; and

increasing consumption of the fuel by the engine relative to consumption of the electrical energy by the motor as degradation of the parameter of the fuel increases.

20. The method of claim 19, where increasing consumption of the fuel includes increasing a duty cycle of the engine relative to a duty cycle of the motor;

and where the parameter of the fuel includes one or more of a volatility of the fuel, a concentration of water in the fuel, and an engine performance obtained from combusting the fuel at the engine.