Series hybrid vehicle capable of operating without a battery

• US 6,692,403 B2
• Filed: 03/13/2002
• Issued: 02/17/2004
• Est. Priority Date: 03/14/2001
• Status: Expired due to Fees

• Current Assignee: Conception ET Developpement Michelin S.A.
• Original Assignee: Conception ET Developpement Michelin S.A.
• Inventors: Magne, Pierre-Alan, Charaudeau, Jean-Jacques
• Primary Examiner(s): Lewis, Tisha D.
• Application Number:
  US10/097,021
• Publication Number:
  US 20020183161A1
• Time in Patent Office: 706 Days
• Field of Search: 477/3, 477/4, 477/7, 477/27, 477/29, 180/65.2, 180/65.3, 180/65.4, 180/65.5, 180/65.8
• US Class Current: 477/3
• CPC Class Codes: B60K 6/34 characterised by the absence of energy storing means
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: B60W 2710/105 Output torque
• 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 10/72 Electric energy management in electromobility

Abstract

A series hybrid vehicle comprising an engine driving an alternator, the engine having a power available at the output shaft of the engine, at least one electric traction motor connected to the alternator by an electric line and an inverter, the inverter allowing the electric traction motor to be operated at a desired torque, the electric line allowing the transfer of an electric traction power, an accelerator control CA at the disposal of the vehicle driver, an actuator acting on the engine, a control device controlling the position of the actuator as a function of the position of the accelerator control, as far as a limitation at least when the desired torque reaches the maximum torque of the electric traction motor, a unit for controlling the propulsion torque of the vehicle, allowing the desired torque to be continuously calculated, in accordance with a chosen sampling period, as a function of the vehicle speed and as a function of a control power P evaluating the power available at the output shaft of the engine as a function of the actual speed of the engine.

Claims

1. A drivetrain for a series hybrid vehicle, comprising:

(a) an engine having an output shaft driving an alternator, the engine having a power available at the output shaft of the engine;

(b) at least one electric traction motor, for generating a propulsion torque, connected to the alternator by an electric line and an inverter, the inverter allowing the electric traction motor to be operated at a desired propulsion torque, the electric line allowing the transfer of an electric traction power;

(c) an accelerator control CA at the disposal of a vehicle driver to control the power available at the output shaft of the engine;

(d) an actuator PP acting on the engine;

(e) a control device controlling the position of the actuator PP as a function of the position of the accelerator control CA, as far as a limitation at least when the desired torque reaches the maximum torque of the electric traction motor; and

(f) a unit for controlling the propulsion torque of the electric traction motor by continuously calculating the desired propulsion torque as a function of a vehicle speed and as a function of a control power P evaluating the power available at the output shaft of the engine as a function of the actual speed of the engine the power available at the output shaft being a result of the operation of the accelerator control CA by the vehicle driver.

2. A drivetrain according to claim 1, in which the control power P is evaluated as follows:

$P=P<br><br>\text{\hspace{1em}<br><br>}<br><br>\max ·<br><br>{\left(\frac{\mathrm{Speed}-\mathrm{Idling}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{speed}}{\mathrm{Max}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{speed}-\mathrm{Idling}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{speed}}\right)}^{\mathrm{Adjustment}},$

where “

Adjustment”

is an operating parameter, “

Speed”

is the speed of the engine at the moment of calculation, “

Idling speed”

is the speed of the engine when idling, and “

Max. speed”

is the speed of the engine used at the point of maximum power.

3. A drivetrain according to claim 2, in which the “

Adjustment”

parameter, from a maximum “

Dyn. Adjust.”

value, tends towards an “

Eco. Adjust.”

value, and rapidly assumes the “

Dyn. Adjust.”

value again in the event of rapid action on the accelerator control CA intending to accelerate the vehicle.

4. A drivetrain according to claim 2, in which the “

Adjustment”

parameter varies between a high value called “

Dyn. Adjust.” and

a low value called “

Min. adjust.”

, with “

Min. adjust.”

being calculated as follows;

$\mathrm{Min}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.=\mathrm{Dyn}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.-\left(v·<br><br>\frac{\mathrm{Dyn}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.-\mathrm{Eco}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.}{\mathrm{Speed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{threshold}}\right)$

where “

v”

is the instantaneous vehicle speed, whose upper limit is the “

Speed threshold”

.

5. A drivetrain according to claim 2, in which the “

Adjustment”

parameter is calculated as follows;

$\mathrm{Adjustment}=\mathrm{Dyn}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.-\left(v·<br><br>\frac{\mathrm{Dyn}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.-\mathrm{Eco}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{adjust}.}{\mathrm{Speed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{threshold}}\right)·<br><br>\left(1-k\right)$

where “

v”

is the instantaneous vehicle speed, whose upper limit is the “

Speed threshold”

, $k=\frac{D}{\mathrm{Max}.\text{\hspace{1em}<br><br>}<br><br>\mathrm{accelerator}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{position}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{derivative}}$

with D=0 when the first derivative with respect to time of the position of the accelerator control CA is negative or zero, and D=the value of the first derivative of the position of the accelerator control CA when the said derivative is positive, with k limited to 1.

6. A drivetrain according to claim 1, further comprising an electrical energy absorption device connected to the electric line via a braking control unit, the braking control unit being activated when the accelerator control CA is below a predetermined threshold, so as to order the control unit to send a desired braking torque C to the electric motor and so as to put the actuator PP into an idling position.

7. A drivetrain according to claim 6, in which the predetermined threshold of the accelerator control CA is proportional to the vehicle speed.

8. A drivetrain according to claim 6, in which the electrical energy absorption device comprises a means for storing the electrical energy.

9. A drivetrain according to claim 8, in which the control device tends first of all to empty the electrical energy storing means in the event of a demand for acceleration of the vehicle indicated by the accelerator control CA, before acting on the actuator PP.

10. A drivetrain according to claim 1, in which the control device for controlling the actuator PP continuously calculates, at each iteration, a limit position as follows:

11. A drivetrain according to claim 1, in which the unit for controlling the propulsion torque of the vehicle calculates the desired torque in accordance with a chosen sampling period.