Regeneration control device of hybrid electric vehicle

• US 6,318,487 B2
• Filed: 02/23/2001
• Issued: 11/20/2001
• Est. Priority Date: 02/24/2000
• Status: Expired due to Fees

• Current Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Yanase, Takashi, Susuki, Yuta
• Primary Examiner(s): Mar, Michael
• Application Number:
  US09/790,656
• Publication Number:
  US 20010020554A1
• Time in Patent Office: 270 Days
• Field of Search: 701/22, 318/8, 318/375, 318/376, 180/65.2, 180/65.3, 180/65.4, 180/65.1, 180/65.8, 180/165
• US Class Current: 180/65.245
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/20 Braking by supplying regenerated power to the prime mover of vehicles comprising engine-driven generators
• 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 10/18 including control of braking systems
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 30/18109 Braking
• 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 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/947 Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A regeneration control device of a hybrid electric vehicle can sufficiently charge a battery with power regenerated as a result of the regenerative braking and effectively perform the regenerative braking, and which can also ease the burden of a friction brake. If chargeable power set by a chargeable power setting device according to an actual level of the battery becomes lower than regenerated power computed by a regenerated power computing unit during the regenerating operation of a motor, the power regenerated by the motor is supplied to a generator. This drives the generator to cause an engine to run an engine brake without the supply of fuel.

Claims

1. A hybrid electric vehicle, comprising:

a generator rotated by a driving force of an engine to thereby generate power;

a battery to which the power generated by said generator is charged;

a motor for generating a driving force to driving wheels of the vehicle by the power supplied from said battery and regenerating energy by using rotational power from the driving wheels to generate power and charge said battery when said vehicle is being braked;

an actual charge level sensing device for sensing an actual charge level of said battery;

a chargeable power setting device for setting chargeable power in accordance with a sensed value of the actual charge level of said battery by said actual charge level sensing device;

a deceleration instruction device for instructing said vehicle to decelerate;

a deceleration torque sensing device for sensing a deceleration torque required by said deceleration instruction device;

a regenerated power computing unit for setting regenerated power to be regenerated by said motor during a regenerative braking according to a sensed value of the required deceleration torque by said deceleration torque sensing device; and

a control device for supplying the power generated by said motor to said generator to thereby drive said generator to rotate said engine when an accelerator pedal for supplying fuel to the engine has not been depressed and when chargeable power set by said chargeable power setting device is less than the regenerated power computed by said regenerated power computing unit while said motor is regenerating the energy.

2. A hybrid electric vehicle according to claim 1, wherein:

said engine has an auxiliary braking device for absorbing rotational energy from said engine, and

said control device controls an operation of said auxiliary braking device according to a difference between said chargeable power and said regenerated power to thereby change a power consumption of said generator.

3. A hybrid electric vehicle according to claim 1, wherein:

said engine has an auxiliary braking device for absorbing rotational energy from said engine, and

said control device determines revolutions, at which said engine is operated with the accelerator pedal not being depressed in, accordance with a difference between said chargeable power and said regenerated power, drives said generator to achieve the determined revolutions, and controls an operation of said auxiliary braking device to change a power consumption of said generator.

4. A hybrid electric vehicle according to claim 1, wherein:

said engine has a plurality of auxiliary braking devices for absorbing rotational energy from said engine; and

said control device selects an operation of said plurality of auxiliary braking devices according to a difference between said chargeable power and said regenerated power.

5. A method of recharging a battery in a hybrid electric vehicle having a battery, a generator activated by a driving force of an engine to charge the battery, a motor activated by power from the battery and regenerates energy by using rotational power from driving wheels of the vehicle to generate power and charge the battery when the vehicle is being braked, comprising:

detecting an actual charge level of the battery;

setting chargeable power in accordance with the detected actual charge level of the battery;

instructing the vehicle to decelerate;

detecting a deceleration torque required in said instructing step;

setting regenerated power to be regenerated by the motor according to the detected deceleration torque; and

supplying power generated by the motor to the generator to thereby drive the generator to run the engine without supplying fuel when the set chargeable power is less than the set regenerated power while the motor is regenerating the energy.

6. The method of claim 5, wherein said supplying step includes the step of controlling an operation of an auxiliary braking device, for absorbing rotational energy from said engine, according to a difference between said set chargeable power and said set regenerated power to thereby change a power consumption of the generator.

7. The method of claim 5, wherein said supplying step includes the steps of,

determining revolutions, at which the engine is operated with the accelerator pedal not being depressed, in accordance with a difference between said set chargeable power and said set regenerated power,

driving the generator to achieve the determined revolutions, and

controlling an operation of an auxiliary braking device, for absorbing rotational energy from said engine, to change power consumption of the generator.

8. The method of claim 5, wherein said supplying step includes the step of selecting an operation of a plurality of auxiliary braking devices, for absorbing rotational energy from said engine, according to a difference between said set chargeable power and said set regenerated power.