Hybrid electric vehicle

• US 9,174,525 B2
• Filed: 09/26/2013
• Issued: 11/03/2015
• Est. Priority Date: 02/25/2013
• Status: Active Grant

• Current Assignee: Fairfield Manufacturing Company, Inc. (Oerlikon USA, Inc. (Florida))
• Original Assignee: Fairfield Manufacturing Company, Inc. (Oerlikon USA, Inc. (Florida))
• Inventors: Caron, LaVerne Andrew
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): BUTLER, RODNEY ALLEN
• Application Number:
  US14/038,740
• Publication Number:
  US 20140244082A1
• Time in Patent Office: 768 Days
• US Class Current: 1/1
• CPC Class Codes: B60K 23/08 for changing number of driven wheels , for switching from driving one axle to driving two or more axles B60K17/3515 takes precedence
• CPC Class Codes: B60K 6/22 characterised by apparatus, components or means specially adapted for HEVs
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 50/13 using AC generators and AC motors
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/00 Conjoint control of vehicle sub-units of different type or different function for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00
• 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: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2556/00 Input parameters relating to data
• CPC Class Codes: B60Y 2200/40 Special vehicles
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02P 25/08 Reluctance motors
• CPC Class Codes: H02P 9/00 Arrangements for controlling electric generators for the purpose of obtaining a desired output Ward-Leonard arrangements H02P7/34; vector control H02P21/00; feeding a network by two or more generators H02J; for charging batteries H02J7/14
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• 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 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A hybrid electric vehicle includes a high voltage DC bus and an internal combustion engine. The internal combustion engine is mechanically coupled to a non self-excited generator/motor which is preferably a switched reluctance machine. A power inverter electrically and bidirectionally couples the high voltage DC bus to the non self-excited switched reluctance generator/motor. Front and rear axle dual DC-AC inverters electrically and bidirectionally couple two traction AC non self-excited switched reluctance motors/gear reducers to the high voltage DC bus for moving the vehicle and for regenerating power. An ultracapacitor coupled to the high voltage DC bus. A bidirectional DC-DC converter interposed between a low voltage battery and the high voltage DC bus transfers energy to the high voltage DC bus and ultracapacitor to ensure that the non self-excited switched reluctance generator/motor operating in the motor mode is able to start the engine.

Claims

1. A method for controlling a hybrid electric vehicle, comprising:

setting the maximum permissible energy content of an ultracapacitor bank;

setting the minimum high voltage DC bus voltage;

determining if there is sufficient energy in said ultracapacitor bank to start an internal combustion engine;

transferring energy using a DC-DC converter from a low voltage DC battery to said ultracapacitor bank if there is not sufficient energy in said ultracapacitor bank to start said internal combustion engine;

starting said internal combustion engine using a non self-excited generator/motor operating in a motor mode to start said internal combustion engine if there is sufficient energy in said ultracapacitor bank;

calculating recoverable energy in said hybrid electric vehicle;

calculating energy in said ultracapacitor bank of said hybrid electric vehicle;

determining if said calculated recoverable energy plus said ultracapacitor energy is less than a maximum permissible energy content of said ultracapacitor bank;

commanding said internal combustion engine to idle and commanding zero power generation from said non self-excited generator/motor operating in a generator mode if said calculated recoverable energy plus said ultracapacitor energy is not less than said maximum permissible energy content of said ultracapacitor bank and waiting a period of time while said internal combustion engine is idling with zero power generation from said non self-excited generator/motor operating in said generator mode and recalculating said calculated recoverable energy plus said ultracapacitor energy and redetermining if said calculated recoverable energy plus said ultracapacitor energy is less than a maximum permissible energy content of said ultracapacitor bank due to consumption of energy by said hybrid electric vehicle and if said recalculated recoverable energy plus said ultracapacitor energy is not less than a maximum permissible energy content of said ultracapacitor bank, then shutting down said internal combustion engine;

setting said internal combustion engine speed to the best brake specific speed and commanding maximum power from said non self-excited generator/motor operating in a generator mode if said calculated recoverable energy plus said ultracapacitor energy is less than said maximum permissible energy content of said ultracapacitor bank;

determining if a brake command is present;

sending a negative torque command to non self-excited traction motors/generators proportional to said brake command and within stability limits if said brake command is present;

determining if the high voltage DC bus voltage is greater than said high voltage DC bus minimum voltage if said brake command is not present;

sending a zero torque command to said non self-excited traction generators/motors if said high voltage DC bus voltage is not greater than said high voltage DC bus minimum voltage;

reading an accelerator command if said high voltage DC bus is greater than said high voltage DC bus minimum voltage;

determining if the vehicle speed is less than the maximum permissible speed;

sending a zero torque command to said non self-excited traction generators/motors if vehicle speed is not less than the maximum permissible speed;

sending a positive torque command proportional to the accelerator signal within stability limits to said non self-excited traction generators/motor if said shift selector is in forward gear; and

,

sending a negative torque command proportional to the accelerator signal within stability limits to said non self-excited traction generators/motors if said shift selector is not in forward gear.

2. A method for controlling a hybrid electric vehicle as claimed in claim 1 wherein said non self-excited traction generators/motors are switched reluctance machines.

3. A method for controlling a hybrid electric vehicle as claimed in claim 1 wherein said non self-excited generator/motor operating for starting said internal combustion engine is a switched reluctance machine.

4. A method for controlling a hybrid electric vehicle as claimed in claim 1 wherein said step of commanding said internal combustion engine to idle and commanding zero power generation from said non self-excited generator/motor operating in a generator mode if said calculated recoverable energy plus said ultracapacitor energy is not less than said maximum permissible energy content of said ultracapacitor bank and waiting a period of time while said internal combustion engine is idling with zero power generation from said non self-excited generator/motor operating in said generator mode and recalculating said calculated recoverable energy plus said ultracapacitor energy and redetermining if said calculated recoverable energy plus said ultracapacitor energy is less than a maximum permissible energy content of said ultracapacitor bank due to consumption of energy by said hybrid electric vehicle and if said recalculated recoverable energy plus said ultracapacitor energy is not less than a maximum permissible energy content of said ultracapacitor bank, then shutting down said internal combustion engine.

5. A method for controlling a hybrid electric vehicle as claimed in claim 1 wherein said step of commanding said internal combustion engine to idle and commanding zero power generation from said non self-excited generator/motor operating in a generator mode if said calculated recoverable energy plus said ultracapacitor energy is not less than said maximum permissible energy content of said ultracapacitor bank and waiting a period of time while said internal combustion engine is idling with zero power generation from said non self-excited generator/motor operating in said generator mode and recalculating said calculated recoverable energy plus said ultracapacitor energy and redetermining if said calculated recoverable energy plus said ultracapacitor energy is less than a maximum permissible energy content of said ultracapacitor bank due to consumption of energy by said hybrid electric vehicle and if said recalculated recoverable energy plus said ultracapacitor energy is not less than a maximum permissible energy content of said ultracapacitor bank, then shutting down said internal combustion engine is performed in conjunction with said dual compact inverters discharging some energy in said ultracapacitor bank into windings of said non self-excited traction generators/motors without motion either by operating at sufficiently low enough power to avoid motion or by operating said non self-excited traction generators/motors with opposing torques to enable safe operation of said vehicle.

6. A method for controlling a hybrid electric vehicle as claimed in claim 1 wherein said ultracapacitor bank is driven to a predetermined maximum state of charge prior to shutdown of said internal combustion engine for rapid engine starting without need to rely on pre-charging from said vehicle low-voltage DC battery.

7. A hybrid electric vehicle, comprising:

a high voltage DC bus;

an internal combustion engine;

said internal combustion engine mechanically coupled to a non self-excited switched reluctance motor/generator;

said non self-excited switched reluctance motor/generator operates as a generator supplying electrical power in a generator mode;

said non self-excited switched reluctance motor/generator operates as a motor receiving electrical power in a motor mode;

said non self-excited switched reluctance generator/motor coupled to an inverter, said inverter bi-directionally conveys power between said high voltage DC bus and said non self-excited switched reluctance generator/motor;

a first front AC traction motor/generator for driving a first front wheel, said first front traction motor/generator being a non self-excited switched reluctance motor/generator, said first front traction motor/generator provides propulsion and/or regenerative braking;

a second front AC traction motor for driving a second front wheel, said second front traction motor/generator being a non self-excited switched reluctance motor/generator, said second front traction motor/generator provides propulsion and/or regenerative braking;

a first rear AC traction motor/generator for driving a first rear wheel, said first rear traction motor/generator being a non self-excited switched reluctance motor/generator, said first rear traction motor/generator provides propulsion and/or regenerative braking;

a second rear AC traction motor/generator for driving a second rear wheel, said second rear traction motor/generator being a non self-excited switched reluctance motor/generator, said second rear traction motor/generator provides propulsion and/or regenerative braking;

a first compact dual inverter and a second compact dual inverter;

said first compact dual inverter in electrical communication with said high voltage DC bus;

said first compact dual inverter converts DC power from said high voltage DC bus into AC power for driving said first front AC traction motor/generator and said first front wheel;

said first compact dual inverter converts DC power from said high voltage DC bus into AC power for driving said second front AC traction motor/generator and said second front wheel;

said second compact dual inverter in electrical communication with said high voltage DC bus;

said second compact dual inverter converts DC power from said high voltage DC bus into AC power for driving said first rear AC traction motor/generator and said first rear wheel;

said second compact dual inverter converts DC power from said high voltage DC bus into AC power for driving said second rear AC traction motor/generator and said second rear wheel;

an ultracapacitor bank, said ultracapacitor bank electrically coupled to said high voltage DC bus;

said ultracapacitor bank stores regenerative energy from said first compact dual inverter supplied by said first and second front AC traction motors/generators operating in a regenerative mode;

said ultracapacitor bank stores regenerative energy from said second compact dual inverter supplied by said first and second rear AC traction motors/generators operating in a regenerative mode;

said ultracapacitor bank stores energy from said inverter coupled to said non self-excited switched reluctance generator/motor when said non self-excited switched reluctance generator/motor is operating in said generator mode;

said ultracapacitor bank supplies energy to said inverter coupled to said non self-excited switched reluctance generator/motor when said non self-excited switched reluctance generator/motor is operating in said motor mode to start said internal combustion engine;

a conventional low voltage system with at least one 12 or 24 volt battery;

a bidirectional DC-DC converter, said DC-DC converter steps said voltage of said battery up and conveys power between said 12 or 24 volt battery and said ultracapacitor bank to pre-charge said ultracapacitor bank to start said internal combustion engine; and

,

said bidirectional DC-DC converter steps said voltage of said high voltage DC bus down to maintain the state of charge of said 12 or 24 volt battery after said internal combustion engine is started.

8. A hybrid electric vehicle as claimed in claim 7, further comprising:

a resistor bank, said resistor bank consumes excess regenerative energy from said non self-excited AC traction generators/motors operating in said regenerative braking mode.

9. A hybrid electric vehicle as claimed in claim 7 in which said non self-excited switched reluctance motor/generator coupled to said internal combustion engine operating in said motor mode is used to dissipate excess kinetic energy from the vehicle by back driving said engine while operating an engine compression brake.

10. A hybrid electric vehicle as claimed in claim 7, wherein said non self-excited switched reluctance generator/motor is the primary source of electrical energy for the vehicle.

11. A hybrid electric system, comprising:

an internal combustion engine;

a non self-exciting AC generator/motor;

said non self-exciting AC generator/motor operates in either a generator mode or a motor mode;

a high voltage DC bus;

an ultracapacitor bank, said ultracapacitor bank connected full time across said high voltage DC bus;

an AC-DC inverter for converting the AC power from said non self-exciting AC generator/motor to DC power for supply to said high voltage DC bus and said ultracapacitor bank;

a low voltage DC battery;

means for charging said ultracapacitor bank from said conventional low-voltage DC battery to provide initial excitation energy to said non self-exciting generator/motor operating in said motor mode to start said internal combustion engine; and

,

said non self-excited generator/motor is operated in said motor mode to back drive said internal combustion engine and an associated engine brake in order to dissipate excessive regenerative braking energy.

12. A hybrid electric system, as claimed in claim 11 in which said ultracapacitor bank is charged with sufficient energy from said low voltage battery such that said non self-excited generator/motor can be used in said motor modes to start said internal combustion engine thus replacing the conventional low-voltage engine starter.

13. A hybrid electric system, as claimed in claim 11 wherein said means used to charge said ultracapacitor is a bi-directional DC-DC converter which maintains the state of charge of said low-voltage battery thus eliminating the need for a conventional low-voltage alternator.

14. A hybrid electric system as claimed in claim 11, wherein said non self-excited generator/motor is a switched reluctance machine.

15. A hybrid electric system, comprising:

an internal combustion engine;

a non self-exciting AC generator/motor;

said non self-exciting AC generator/motor operates in either a generator mode or a motor mode;

a high voltage DC bus;

an ultracapacitor bank, said ultracapacitor bank connected full time across said high voltage DC bus;

an AC-DC inverter for converting the AC power from said non self-exciting AC generator/motor to DC power for supply to said high voltage DC bus and said ultracapacitor bank;

a low voltage DC battery;

means for charging said ultracapacitor bank from said conventional low-voltage vehicle DC battery to provide initial excitation energy to said non self-exciting generator/motor operating in said motor mode to start said internal combustion engine;

dual compact inverters;

a plurality of wheels;

a plurality of non self-excited traction generators/motors each interconnected with a respective one of said plurality of wheels;

said dual compact inverters are connected across said ultracapacitor bank;

said dual compact inverters are bidirectional DC-AC inverters;

said dual compact inverters transfer energy to and from said ultracapacitor bank and to and from said non self-excited traction generators/motors; and

,

one or more of said dual compact inverters discharge some energy in said ultracapacitor bank into the windings of said non self-excited traction generators/motors without motion either by operating at sufficiently low enough power to avoid motion or by operating said non self-excited traction generators/motors with opposing torques to enable safe operation of said system.

16. A hybrid electric system, comprising:

an internal combustion engine;

a non self-exciting AC generator/motor;

said non self-exciting AC generator/motor operates in either a generator mode or a motor mode;

a high voltage DC bus;

an ultracapacitor bank, said ultracapacitor bank connected full time across said high voltage DC bus;

an AC-DC inverter for converting the AC power from said non self-exciting AC generator/motor to DC power for supply to said high voltage DC bus and said ultracapacitor bank;

a low voltage DC battery;

means for charging said ultracapacitor bank from said conventional low-voltage DC battery to provide initial excitation energy to said non self-exciting generator/motor operating in said motor mode to start said internal combustion engine; and

,

said ultracapacitor bank is driven to a predetermined maximum state of charge prior to engine shutdown in order to provide for rapid engine starting without need to rely on pre-charging from said vehicle low-voltage DC battery under normal operating conditions.