Power supply device, control method of power supply device, and motor vehicle equipped with power supply device

• US 7,839,116 B2
• Filed: 04/14/2006
• Issued: 11/23/2010
• Est. Priority Date: 04/15/2005
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Esaka, Toshinori, Okabe, Nobuyuki, Komeda, Osamu
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Fantu; Yalkew
• Application Number:
  US11/887,572
• Publication Number:
  US 20090015193A1
• Time in Patent Office: 1,684 Days
• Field of Search: 320/103
• US Class Current: 320/103
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• 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 2510/244 Charge state
• CPC Class Codes: B60W 2710/244 Charge state
• CPC Class Codes: B60Y 2400/112 Batteries
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• 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

Abstract

In a power supply device of the invention, when the state of charge SOC1 of a low-voltage battery is lower than a discharging reference value Shi1 below a full charge level and when the state of charge SOC2 of a high-voltage battery is not lower than a discharging reference value Slow2 at a system-off time, the low-voltage battery is charged close to its full charge level with the electric power supplied from the high-voltage battery. The lead acid battery used for the low-voltage battery has the high potential for deterioration in the continuously low state of charge SOC. The lithium secondary battery used for the high-voltage battery has the high potential for deterioration in the continuously high state of charge SOC. The charge of the low-voltage battery in combination with the discharge of the high-voltage battery enables both the low-voltage battery and the high-voltage battery to have respective favorable states of charge with little potentials for deterioration. The technique of the invention thus effectively prevents quick deterioration of both the low-voltage battery and the high-voltage battery.

Claims

1. A power supply device incorporated in a system and receives a supply of electric power from the system and supplies electric power to a system electric power-consuming apparatus, said power supply device comprising:

a first battery that is chargeable and dischargeable and has a first characteristic which is quick deterioration in a low state of charge having a low level of dischargeable electric power;

a second battery that is chargeable and dischargeable and has a second characteristic which is quick deterioration in a high state of charge having a high level of dischargeable electric power;

a voltage adjustment structure that adjusts a first voltage as a voltage of a first voltage system connected with the first battery and a second voltage of a second voltage system connected with the second battery;

a first state of charge computation module that computes a first state of charge as a dischargeable electric power from the first battery based on the state of the first battery;

a second state of charge computation module that computes a second state of charge as a dischargeable electric power from the second battery based on the state of the second battery; and

a control module that, when the system is off, under condition that the computed first state of charge is less than a first predetermined state of charge which is lower than a state of charge at a full charge level and the computed second state of charge is more than a second predetermined state of charge which is chargeable of the first battery, controls said voltage adjustment structure to cause the state of charge of the first battery to become more than the first predetermined state of charge by transmission of electric power between the first battery and the second battery.

2. A power supply in accordance with claim 1, wherein the first battery is a battery that has a characteristic which a battery performance is regenerated by shifting a high state of charge having a high level of dischargeable electric power and a low state of charge having a low level of dischargeable electric power, and

said control module that, when the system is off, under condition that the computed first state of charge is more than the first predetermined state of charge and the second state of charge is more than a third predetermined state of charge which is acceptable of electric power from the first battery, controls said voltage adjustment structure to cause the state of charge of the first battery to become more than the first predetermined state of charge after the state of charge of the first battery becomes a forth predetermined state of charge that is a high state of charge having a low level of dischargeable electric power by transmission of electric power between the first battery and the second battery.

3. A power supply device in accordance with claim 1, wherein the first battery is a lead acid battery;

and

the second battery is a lithium secondary battery.

4. A motor vehicle, comprising:

an internal combustion engine;

a generator that consumes output power of the internal combustion engine and generates electric power; and

a power supply device that receives a supply of the electric power generated by the generator and supplies electric power to an electric power-consuming apparatus equipped on the motor vehicle, said power supply device comprising;

a first battery that is chargeable and dischargeable and has a first characteristic which is quick deterioration in a low state of charge having a low level of dischargeable electric power;

a second battery that is chargeable and dischargeable and has a second characteristic which is quick deterioration in a high state of charge having a high level of dischargeable electric power;

a voltage adjustment structure that adjusts a first voltage as a voltage of a first voltage system connected with the first battery and a second voltage as a voltage of a second voltage system connected with the second battery;

a first state of charge computation module that computes a first state of charge as a dischargeable electric power from the first battery based on the state of the first battery;

a second state of charge computation module that computes a second state of charge as a dischargeable electric power from the second battery based on the state of the second battery; and

a control module that, when the vehicle is system-off, under condition that the computed first state of charge is less than a first predetermined state of charge which is lower than a state of charge at a full charge level and the computed second state of charge is more than a second predetermined state of charge which is chargeable of the first battery, controls said voltage adjustment structure to cause the state of charge of the first battery to become more than the first predetermined state of charge by transmission of electric power between the first battery and the second battery.

5. A control method of a power supply device incorporated in a system and receives a supply of electric power from the system and supplies electric power to a system electric power-consuming apparatus, said power supply device comprising:

a first battery that is chargeable and dischargeable and has a first characteristic which is quick deterioration in a low state of charge having a low level of dischargeable electric power;

a second battery that is chargeable and dischargeable and has a second characteristic which is quick deterioration in a high state of charge having a high level of dischargeable electric power;

a voltage adjustment structure that adjusts a first voltage as a voltage of a first voltage system connected with the first battery and a second voltage as a voltage of a second voltage system connected with the second battery,

under condition that, when the system is off, a first state of charge as dischargeable electric power from the first battery based on the state of the first battery is less than a first predetermined state of charge which is lower than a state of charge at a full charge level and a second state of charge as dischargeable electric power from the second battery based on the state of the second battery is more than a second predetermined state of charge which is chargeable of the first battery, controls said voltage adjustment structure to cause the state of charge of the first battery to become more than the first predetermined state of charge by transmission of electric power between the first battery and the second battery.