Generator controller and controlling method for hybrid vehicle

• US 5,550,445 A
• Filed: 09/08/1994
• Issued: 08/27/1996
• Est. Priority Date: 09/24/1993
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nii, Yoshihide
• Primary Examiner(s): Cabeca, John W.
• Application Number:
  US08/302,412
• Time in Patent Office: 719 Days
• Field of Search: 318/153, 318/138, 318/140, 318/151, 318/152, 318/154, 322/23, 322/8, 322/38, 322/39, 322/15, 322/16, 301/18, 301/31, 301/23, 301/52, 301/54, 180/65.2, 180/65.4, 180/65.1, 180/65.3
• US Class Current: 318/153
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• 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 10/26 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 2510/244 : Charge state
• CPC Class Codes: B60W 2710/065 : Idle condition
• CPC Class Codes: B60W 2710/086 : Power
• CPC Class Codes: H02J 7/1415 : with a generator driven by a prime mover other than the motor of a vehicle
• 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

Abstract

A generator controller and controlling method of a hybrid vehicle. A battery voltage is compared with a predetermined value and when the battery voltage is lower than the predetermined value as a result of the comparison, an state of charge of the battery is discriminated. In the case of an state of charge of at least 70%, a generator output is controlled on the basis of a motor output, and in the case of an state of charge of less than 70%, while the generator output is controlled to a relatively high value, the motor output is limited. When the state of charge is restored to more than 75%, the voltage is controlled depending on the motor output. In the case of at least the predetermined value of the battery voltage, an idle control of an engine is carried out. As a result, the state of charge of the battery can be ensured and overcharging of the battery can be prevented.

Claims

1. A generator controller for controlling an operation of a generator mounted on a hybrid vehicle, said hydrid vehicle including a battery for supplying electric power to a motor, the generator for supplying electric power to the motor and the battery, and an engine for driving the generator, comprising:

means for detecting a heavy load state in which a battery charge state is reduced to less than a predetermined value;

means for carrying out an increase control of an output of the generator and for limiting an output of the motor so that, when the heavy load state is detected, the generator output is used, for a certain period, to charge the battery, and

means for either stopping or avoiding the increase control of the generator output and the output limitation of the motor when at least heavy load state is not detected.

2. The generator controller of claim 1, further comprising:

means for detecting the battery charge reaching at least a predetermined level as voltage increased condition, which exists when the battery voltage becomes at least a predetermined voltage;

means for carrying out an idle control of the engine and a generation stop control of the generator when the voltage increased condition is detected; and

means for either stopping or avoiding the idle control of the engine and the generation stop control of the generator when at least the voltage increased condition is not detected.

3. The generator controller of claim 2, further comprising:

means for gradually decreasing the output of the generator to a predetermined value when at least the idle control of the engine and the generation stop control of the generator are executed; and

means for gradually increasing the output of the generator to an equivalent value required for the motor output.

4. The generator controller of claim 2, further comprising means for either stopping or avoiding the idle control of the engine and the generation stop control of the generator only when the voltage increase state continues for a predetermined time of period.

5. The generator controller of claim 2, wherein the idle control of the engine and the generation stop control of the generator are maintained for at least a predetermined time.

6. The generator controller of claim 1, further comprising:

means for detecting the output of the motor; and

means for flattening the detected motor output and controlling the output of the generator on the basis of a value obtained by adding a limitation, corresponding to a generation output range of the generator, to the motor output.

7. The generator controller of claim 2, further comprising:

means for detecting the output of the motor; and

means for flattening the detected motor output and controlling the output of the generator on the basis of a value obtained by adding a limitation, corresponding to a generation output range of the generator, to the motor output.

8. The generator controller of claim 3, further comprising:

means for detecting the output of the motor; and

means for flattening the detected motor output and controlling the output of the generator on the basis of a value obtained by adding a limitation, corresponding to a generation output range of the generator, to the motor output.

9. The generator controller of claim 8, wherein the flattening is executed by integrating.

10. The generator controller of claim 8, further comprising means for multiplying the detected motor output by a factor considering efficiency prior to the flattening.

11. The generator controller of claim 1, further comprising means for carrying out a limitation control of the output of the generator when the charge state of the battery becomes at least a predetermined value owing to the increase control of the generator output and the output limitation of the motor.

12. The generator controller of claim 1, further comprising means for controlling the output of the generator depending on the charge state of the battery when the charge state of the battery becomes at least a predetermined value owing to the increase control of the generator output and the output limitation of the motor.

13. A generator controlling method for controlling an operation of a generator, executed on a hybrid vehicle including a battery for supplying electric power to a motor, the generator for supplying electric power to the motor and the battery, and an engine for driving the generator, comprising:

a step for detecting a heavy load state in which a battery charge state is reduced to less than a predetermined value;

a step for carrying out an increase control of an output of the generator and for limiting an output of the motor so that, when the heavy load state is detected, the generator output is used, for a certain period, for charging the battery; and

a step for either stopping or avoiding the increase control of the generator output and the output limitation of the motor when at least the heavy load state is not detected.

14. The generator controlling method of claim 13, further comprising:

a step for detecting the battery charge reaching at least a predetermined level as voltage increased condition, which exists when the battery voltage becomes at least a predetermined voltage;

a step for carrying out an idle control of the engine and a generation stop control of the generator when the voltage increased condition is detected; and

a step for either stopping or avoiding the idle control of the engine and the generation stop control of the generator when at least the voltage increased condition is not detected.

15. The generator controlling method of claim 14, further comprising:

a step for gradually decreasing the output of the generator to a predetermined value when the idle control of the engine and the generation stop control of the generator are executed; and

a step for gradually increasing the output of the generator to an equivalent value required for the motor output.

16. The generator controlling method of claim 13, further comprising:

a step for detecting the output of the motor; and

a step for flattening the detected motor output and controlling the output of the generator on the basis of a value obtained by adding a limitation corresponding to a generation output range of the generator to the motor output.