Hybrid vehicles incorporating turbochargers

• US 6,338,391 B1
• Filed: 09/09/1999
• Issued: 01/15/2002
• Est. Priority Date: 03/01/1999
• Status: Expired due to Term

• Current Assignee: Abell Foundation Incorporated
• Original Assignee: Paice LLC
• Inventors: Louckes, Theodore, Severinsky, Alex J.
• Primary Examiner(s): Swann, J. J.
• Assistant Examiner(s): Dunn, David R.
• Application Number:
  US09/392,743
• Time in Patent Office: 859 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.4, 180/65.8, 180/165, 607/06, 607/11, 607/16, 607/18, 606/02, 290/17, 290/40.R, 290/40.C, 322/16, 477/2, 477/3
• US Class Current: 180/65.23
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/443 Torque
• 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: B60L 58/12 responding to state of charge [SoC]
• 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 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0633 Turbocharger state
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60Y 2400/435 Supercharger or turbochargers
• CPC Class Codes: F02B 37/18 : by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02D 41/0007 : for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02N 11/0818 : Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• 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 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A hybrid vehicle comprising an internal combustion engine controllably coupled to road wheels of the vehicle by a clutch, and having a turbocharger that is operated only when extra power is needed for a extended time, a traction motor coupled to road wheels of said vehicle, a starting motor coupled to the engine, both motors being operable as generators, a battery bank for providing electrical energy to and accepting energy from said motors, and a microprocessor for controlling these components, is operated in different modes, depending on its instantaneous torque requirements, the state of charge of the battery bank, and other operating parameters. The mode of operation is selected by the microprocessor in response to a control strategy.

Claims

1. A hybrid vehicle, comprising:

a controller capable of accepting inputs indicative of vehicle operating parameters and providing control signals in response to a control program;

a battery bank;

an internal combustion engine, comprising a turbocharger that is operable in response to control signals from said controller;

a first electric motor electrically coupled to said battery bank for (a) accepting electrical energy from said battery bank and (b) providing electrical energy to said battery bank, and said first motor being mechanically coupled to said internal combustion engine, the combination of said internal combustion engine and said first electric motor being mechanically coupled to a clutch controlled by said controller for controllable torque-transmitting connection between said combination and road wheels of said vehicle,

said first motor being responsive to commands from said controller, such that said first electric motor can be controlled to (1) accept torque from said engine to charge said battery bank, (2) accept energy from said battery bank to apply torque to said engine for starting said engine, (3) accept energy from said battery bank to apply torque to said road wheels to propel said vehicle, and (4) accept torque from said road wheels to charge said battery bank; and

a second electric motor, electrically coupled to said battery bank, such that said second electric motor can be controlled for (a) accepting electrical energy from said battery bank and (b) providing electrical energy to said battery bank, said second motor being mechanically coupled to road wheels of said vehicle and being responsive to commands from said controller in order to control said second electric motor to (1) accept energy from said battery bank to apply torque to said road wheels to propel said vehicle, and (2) accept torque from said road wheels to charge said battery bank; and

wherein said controller monitors the instantaneous road load experienced by said vehicle as a function of time, and causes said turbocharger to operate, increasing the maximum output torque of said engine, only when the instantaneous road load exceeds the engine'"'"'s normally-aspirated maximum torque output for more than a predetermined period of time.

2. The hybrid vehicle of claim 1, wherein said controller is provided with signals indicative of the instantaneous road load experienced by said vehicle and of the state of charge of said battery bank, and controls operation of said engine, said clutch, said first and second motors, and said turbocharger, so that said vehicle is operated in a plurality of operating modes responsive to said signals.

3. The hybrid vehicle of claim 2, wherein said signal indicative of the instantaneous road load experienced by said vehicle is determined by said controller at least in part by monitoring commands provided by the vehicle operator.

4. The hybrid vehicle of claim 2, wherein road load (RL) is expressed as a percentage of the maximum torque output of the engine while normally-aspirated (MTO), and said operating modes include:

a low-speed mode I, wherein said vehicle is propelled by torque provided by said traction motor in response to energy supplied from said battery bank, while RL<

SP, wherein SP is a setpoint expressed as a predetermined percentage of MTO,

a highway cruising mode IV, wherein said vehicle is propelled by torque provided by said engine in response to supply of combustible fuel, while SP<

RL<

100% of MTO,

an acceleration mode V, wherein said vehicle is propelled by torque provided by said engine in response to supply of combustible fuel and by torque provided by said traction motor in response to energy supplied from said battery bank, while RL>

100% of MTO, and

a high-power mode VI, wherein said turbocharger is operated such that said vehicle is propelled by torque provided by said engine in response to supply of combustible fuel while RL>

100% of MTO for more than a predetermined time T.

5. The hybrid vehicle of claim 4, wherein said clutch is disengaged during operation in mode I and engaged during operation in modes IV, V, and VI.

6. The hybrid vehicle of claim 4, wherein said time T is controlled responsive to the state of charge of the battery bank.

7. A method for controlling the operation of a hybrid vehicle operable in a plurality of differing modes, said vehicle comprising an internal combustion engine for providing torque up to a maximum normally-aspirated torque output (MTO), said engine being controllably coupled to road wheels of said vehicle by a clutch, a turbocharger being operatively and controllably coupled to said engine for increasing the maximum torque output of said engine to more than MTO when desired, a traction motor being coupled to road wheels of said vehicle, a starting motor coupled to said engine, both said motors being operable as generators, a battery bank for providing electrical energy to and accepting energy from said motors, and a controller for controlling operation of said engine, clutch, turbocharger, and first and second motors, and controlling flow of electrical energy between said motors and said battery bank,

wherein according to said method, said controller controls selection of the operational mode of said vehicle between a low-speed mode I, a cruising mode IV, an acceleration mode V, and a sustained high-power mode VI, wherein torque to propel said vehicle is provided by said traction motor, said engine, both said traction motor and said engine, and said engine with said turbocharger operating, respectively, in response to monitoring the instantaneous torque requirements (RL) of the vehicle.

8. The method of claim 7, wherein said controller controls said vehicle to operate in said low speed mode I while RL<

SP, wherein SP is a setpoint expressed as a predetermined percentage of MTO,

in said highway cruising mode IV while SP <

RL<

100% of MTO,

in said acceleration mode V while RL>

100% of MTO, and

in said sustained high-power mode VI while RL>

100% of MTO for more than a predetermined time T.

9. The method of claim 8, comprising the further step of disengaging said clutch during operation in mode I and engaging said clutch during operation in modes IV, V, and VI.

10. The method of claim 8, wherein said time T is controlled responsive to the state of charge of the battery bank.

11. A method for determining the relative sizes of the internal combustion engine, starting/charging and traction motors, and battery bank of a hybrid vehicle of given weight comprising said components, said method comprising the steps of:

a. Selecting a normally-aspirated internal combustion engine sized such that the engine is required to generate at least about 30% of its maximum torque output while propelling said vehicle at medium to high speed along a moderate grade;

b. Sizing the starting/charging motor to provide an engine load during battery charging equal to at least about 30% of the maximum torque output of the engine selected in step (a);

c. Sizing the traction motor with respect to the weight of said vehicle to provide adequate torque at zero speed to overcome the maximum grade specified from rest, with the starting/charging motor selected in step (b) assisting as needed;

d. Selecting the torque vs. speed profile of the traction motor selected in step (c) to allow convenient city driving, without use of torque from the engine; and

e. Sizing the battery capacity with respect to the starting/charging motor selected in step (b) to be sufficient to avoid excessively frequent discharging and charging cycles, while being able to accept charging current responsive to said engine load during battery charging being equal to at least about 30% of the engine'"'"'s maximum torque output; and

f. Sizing the battery power capacity to provide sufficient power to both motors to provide desired maximum acceleration.

12. The method of claim 11, wherein said engine is provided with a turbocharger controlled to increase the engine'"'"'s maximum torque output during extended operation at high power, wherein the turbocharger increases the engine'"'"'s maximum torque output by at least about 25%.

13. The method of claim 11, wherein the maximum power delivered to the wheels of said vehicle by said normally-aspirated engine is less than or equal to the maximum power delivered to the wheels of said vehicle by said starting/charging and traction motors.

14. A method for determining the relative sizes of the internal combustion engine, starting/charging and traction motors, and battery bank of a hybrid vehicle comprising said components, said method comprising the steps of:

a. Selecting an internal combustion engine that is provided with a turbocharger so as to be operable in normally-aspirated and turbocharged modes of operation, wherein the turbocharger increases the engine'"'"'s normally-aspirated maximum torque output by at least about 25%, and wherein said engine is sized do that the engine generates at least about 30% of its maximum output torque, while propelling the vehicle without trailer at medium to high speed along a moderate grade in normally-aspirated mode;

b. Sizing the starting/charging motor to provide an engine load during battery charging equal to at least about 30% of the engine'"'"'s maximum torque output;

c. Sizing the traction motor to provide adequate torque at zero speed to overcome the maximum grade specified from rest, with the starter motor assisting as needed;

d. Selecting the torque vs. speed profile of the traction motor to allow convenient city driving, without use of torque from the engine; and

e. Sizing the battery capacity to be sufficient to avoid excessively frequent discharging and charging cycles, while being able to accept charging current responsive to said engine load during battery charging being equal to at least about 30% of the engine'"'"'s maximum torque output; and

f. Sizing the battery power capacity to provide sufficient power to both motors to provide desired maximum acceleration.

15. The method of claim 14, wherein the maximum power delivered to the wheels of said vehicle by said engine in normally-aspirated mode is less than or equal to the maximum power delivered to the wheels of said vehicle by said starting/charging and traction motors.