Method and device for controlling generator for hybrid vehicle

• US 5,778,997 A
• Filed: 01/17/1996
• Issued: 07/14/1998
• Est. Priority Date: 01/19/1995
• Status: Expired due to Fees

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Setaka, Yousuke, Banzai, Keiichiro
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US08/583,751
• Time in Patent Office: 909 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/65.6, 290/8, 290/9, 290/10, 290/11, 290/14, 290/16, 290/17, 290/45, 290/70, 318/139, 318/140, 318/141, 318/803, 318/142, 318/143
• US Class Current: 180/65.245
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• 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 58/22 Balancing the charge of battery modules
• 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: 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 10/70 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 is controlled by a controller to generate power sufficient to a battery quickly in addition to power which is required by a wheel-drive motor for a while after a car is started and until a battery charging ratio becomes higher than a first predetermined ratio, between 80% and 100% for example. When the battery charging ratio becomes higher than the first predetermined ratio, the generator is controlled to generate a regulated power which is obtained by adding a constant power to the mean value of the power required by the wheel-drive motor to prevent the battery from generating gases due to overcharging. When the battery-charging ratio further increases and becomes higher than a second predetermined ratio, 120% for example, the generator is controlled to generate less power than the requirement of the wheel-drive-motor.

Claims

1. A method for controlling a generator for a series-hybrid car including an engine-driven generator, an assembled battery, and a wheel-drive motor energized by said generator and said battery, said method comprising the steps of:

detecting current wheel-drive-motor power;

memorizing said current wheel-drive-motor power once in a set time;

detecting battery charging state; and

controlling said generator to generate output power in accordance with said battery charging state, wherein

said step of controlling said generator comprises a first step of controlling said generator to generate maximum output power if said charging state of said battery is lower than a first level; and

when said charging state becomes higher than said first level, a second step of controlling said generator to generate output power which is a sum of a fixed power and said current wheel-drive-motor power memorized during said step of memorizing.

2. A method for controlling a generator as claimed in claim 1 wherein said step of controlling said generator further comprises a third step of controlling said generator to generate less output power than said wheel-drive-motor power which is memorized during said step of memorizing, when said charging state becomes higher than a second level.

3. A method for controlling a generator as claimed in claim 1 or claim 2 further comprising a step of holding said step of controlling said generator for a predetermined time after said generator is started.

4. A method for controlling a generator as claimed in claim 1 or claim 2 further comprising a step of holding said step of controlling said generator for a predetermined travel distance of said car after said generator is started.

5. A method for controlling a generator for a series-hybrid car including an engine-driven generator, a battery, wheel-drive motor energized by said generator and said battery, a battery-current sensor, a generator-current sensor, a battery-voltage sensor and a wheel-drive-motor power detecting unit, said method comprising:

a first step of controlling said generator to generate more output power than said wheel-drive-motor power to charge said battery when said charging state of said battery is under a first level; and

a second step of controlling said generator to generate output power to charge said battery with regulated power which is given by adding a fixed power to a previously detected value of said wheel-drive-motor power when said charging state becomes higher than said first level,

wherein said second step comprises;

a step of sampling a plurality of data of said wheel-drive motor power in a fixed time;

a step of calculating an arithmetical mean value of said plurality of data; and

a step of adding said fixed power to said arithmetical mean value.

6. A device for controlling a generator for a series-hybrid car including an engine-driven generator, a battery connected to said generator, and a wheel-drive motor energized by said generator and said battery, said device comprising:

a power detecting unit for detecting motor power;

a memory for storing a current motor power once in a set time;

a battery charge detecting unit for detecting a charging ratio of said battery;

a first charging control unit for controlling said generator to generate maximum output power when said charging ratio is lower than a first level; and

a second charging control unit for controlling said generator to generate regulated output power which is a sum of a fixed power and said current motor power when said charging ratio is higher than said first level.

7. A device for controlling a generator as claimed in claim 6, wherein said first charging control unit comprises means for holding battery charge for a fixed time period after said generator is turned on.

8. A device for controlling a generator as claimed in claim 6, wherein said first charging control unit comprises means for holding battery charge for a fixed travel distance of said car after said generator is turned on.

9. A device for controlling a generator for a series-hybrid car including an engine-driven generator, a battery connected to said generator, and a wheel-drive motor energized by said generator and said battery, said device comprising:

a power detecting unit for periodically detecting motor power;

a circuit providing an arithmetical mean value of said motor power which is periodically detected in a preceding period;

a battery charge detecting unit for detecting a charging ratio of said battery;

first means for controlling said generator to generate maximum output power to charge said battery when said charging ratio is lower than a first level between 50% and 80%; and

second means for controlling said generator to generate regulated output power which is a sum of a fixed value and said arithmetical mean value when said charging ratio is higher than said first level.

10. A device for controlling a generator as claimed in claim 9, wherein said first charging control unit comprises means for holding battery charge for a fixed time period after said generator is turned on.

11. A device for controlling a generator as claimed in claim 9, wherein said first charging control unit comprises means for holding battery charge for a fixed travel distance of said car after said generator is turned on.

12. A device for controlling a generator as claimed in claim 9 further comprising a third means for controlling said generator to generate less output power than said arithmetical mean value when said charging ratio becomes higher than a second level between 100% and 120%.