Electric energy charging control apparatus and method for hybrid vehicle

• US 20010024104A1
• Filed: 03/13/2001
• Published: 09/27/2001
• Est. Priority Date: 03/23/2000
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Suzuki, Naoto
• Granted Patent: US 6,344,732 B2
• Time in Patent Office: Days
• US Class Current: 320/104
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/662 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: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/24 including control of energy storage means
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/305 Power absorbed by auxiliaries
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2530/00 Input parameters relating to vehicle conditions or values, not covered by groups B60W2510/00 or B60W2520/00
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/244 Charge state
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• 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: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor

Abstract

A controller predicts a requested state of charge/discharge corresponding to a future run of a hybrid vehicle. If it is predicted that the hybrid vehicle will be stopped and restarted, or will be greatly accelerated and therefore that a request for a great discharge will be outputted in the future, the controller increases a target SOC of an HV battery to increase the value to which the charge of the HV battery will be converged in preparation for the great discharge. If it is predicted that a great regenerative electric power will be generated by a vehicle deceleration and therefore that a request for charging will be outputted, the target SOC is reduced, and the amount of charge in the HV battery is reduced, so that the regenerative power generated can be efficiency recovered.

Claims

1. An electric energy charging control apparatus of a hybrid vehicle having an internal combustion engine, a motor-generator capable of assisting running of the vehicle and an electric energy storage device connected to the motor-generator, the control apparatus comprising a controller that:

predicts a future state of a charge/discharge of the electric energy storage device; and

changes a target value of charge of the electric energy storage device based on a result of the prediction regarding the future state of the charge/discharge of the electric energy storage device.

2. The electric energy charging control apparatus according to

claim 1

, wherein the controller predicts the future state based on a state of the run of the vehicle, and changes the target value by:

increasing the target value of charge when the state of the run of the vehicle is a state in which at least a predetermined amount of the charge is predicted to be discharged from the electric energy storage device, and by

reducing the target value of charge when the state of the run of the vehicle is a state in which at least a predetermined amount of the charge is predicted to be charged into the electric energy storage device.

3. The electric energy charging control apparatus according to

claim 1

, wherein the controller changes the target value of charge of the electric energy storage device in accordance with a vehicle ambient temperature.

4. The electric energy charging control apparatus according to

claim 2

, wherein the state of the run of the vehicle is a vehicle speed of the vehicle.

5. The electric energy charging control apparatus according to

claim 4

, wherein

if the vehicle speed of the vehicle is a low vehicle speed for a predetermined time, the controller increases the target value of charge of the electric energy storage device to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of the vehicle being stopped or greatly accelerated.

6. The electric energy charging control apparatus according to

claim 4

, wherein

if the vehicle speed of the vehicle speed is a high vehicle speed for a predetermined time, the controller decreases the target value of charge of the electric energy storage device to increase a region for recovery of a regenerative energy that is to be obtained through the motor-generator in anticipation of a future state of the vehicle being decelerated.

7. The electric energy charging control apparatus according to

claim 6

, wherein:

a quantity of charge of the electric energy storage device corresponding to the decrease in the target value of charge is used by the motor-generator to assist in driving the vehicle, thereby reducing the output of the internal combustion engine and improving fuel economy.

8. The electric energy charging control apparatus according to

claim 3

, wherein

if the vehicle ambient temperature of the vehicle is lower than a predetermined temperature, the controller increases the target value of charge of the electric energy storage device to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of a low charging/discharging efficiency.

9. The electric energy charging control apparatus according to

claim 3

, wherein

if the vehicle ambient temperature of the vehicle is at least equal to a predetermined temperature, the controller only slightly increases the target value of charge of the electric energy storage device to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of a normal start or acceleration.

10. A electric energy charging control method for a hybrid vehicle including an internal combustion engine, a motor-generator capable of assisting a run of the vehicle, and a electric energy storage device connected to the motor-generator, the method comprising:

predicting a future state of charge/discharge of the electric energy storage device; and

changing a target value of charge of the electric energy storage device based on a result of the prediction regarding the future state of the charge/discharge of the electric energy storage device.

11. The electric energy charging control method according to

claim 10

, wherein the future state of charge/discharge of the electric energy storage device is predicted based on a state of the run of the vehicle, and wherein:

the target value of charge is increased if, from the state of the run of the vehicle, at least a predetermined amount of the charge is predicted to be discharged from the electric energy storage device at a future time, and

the target value of charge is reduced if, from the state of the run of the vehicle, at least a predetermined amount of the charge is predicted to be charged into the electric energy storage device at the future time.

12. The electric energy charging control method according to

claim 10

, wherein the target value of charge of the electric energy storage device is changed in accordance with a vehicle ambient temperature.

13. The electric energy control method according to

claim 11

, wherein the state of the run of the vehicle is a vehicle speed of the vehicle.

14. The electric energy charging control method according to

claim 13

, wherein:

if the vehicle speed of the vehicle is a low vehicle speed for a predetermined time, the target value of charge of the electric energy storage device is increased to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of the vehicle being stopped or greatly accelerated.

15. The electric energy charging control method according to

claim 13

, wherein:

if the vehicle speed of the vehicle speed is a high vehicle speed for a predetermined time, the target value of charge of the electric energy storage device is decreased to increase a region for recovery of a regenerative energy that is to be obtained through the motor-generator in anticipation of a future state of the vehicle being decelerated.

16. The electric energy charging control method according to

claim 15

, wherein:

a quantity of charge of the electric energy storage device corresponding to the decrease in the target value of charge is used by the motor-generator to assist in driving the vehicle thereby reducing the output of the internal combustion engine and improving fuel economy.

17. The electric energy charging control method according to

claim 12

, wherein

if the vehicle ambient temperature of the vehicle is lower than a predetermined temperature, the target value of charge of the electric energy storage device is increased to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of a low charging/discharging efficiency.

18. The electric energy charging control method according to

claim 12

, wherein:

if the vehicle ambient temperature of the vehicle is at least equal to a predetermined temperature, the target value of charge of the electric energy storage device is only slightly increased to secure an amount of charge at least equal to an amount of charge that will be consumed by the motor-generator in anticipation of a normal start or acceleration.