Power supply device, electrically-driven vehicle incorporating power supply device, and method of controlling power supply device

• US 7,773,353 B2
• Filed: 02/01/2007
• Issued: 08/10/2010
• Est. Priority Date: 02/03/2006
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Uchida, Kenji
• Primary Examiner(s): Jackson; Stephen W
• Assistant Examiner(s): PATEL, DHARTI HARIDAS
• Application Number:
  US12/087,681
• Publication Number:
  US 20090002903A1
• Time in Patent Office: 1,286 Days
• Field of Search: 361/49
• US Class Current: 361/49
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 3/00 Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption methods or circuit arrangements for monitoring or controlling batteries or fuel cells B60L58/00
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: G01R 27/025 Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
• CPC Class Codes: G01R 31/42 AC power supplies
• CPC Class Codes: H02J 2310/22 The load being a portable electronic device
• CPC Class Codes: H02J 3/322 the battery being on-board an electric or hybrid vehicle, e.g. vehicle to grid arrangements [V2G], power aggregation, use of the battery for network load balancing, coordinated or cooperative battery charging
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• 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 90/14 Plug-in electric vehicles

Abstract

An ECU determines based on a voltage from an insulation resistance decrease detector whether the insulation resistance of a power supply device decreases or not. When a load external to the vehicle is not connected to the power supply device, the ECU sets a determination threshold value for determining that the insulation resistance decreases to a normal first value. On the other hand, when the load external to the vehicle is electrically connected to the power supply device, the ECU sets the determination threshold value to a second value which is lower than the first value, in consideration of an increase in the capacitive component due to a capacitor of a Y-capacitor.

Claims

1. A power supply device incorporated in an electrically-driven vehicle, comprising:

a power storage device;

an electric power conversion device configured to allow at least one of power feeding from said power storage device to a load external to the vehicle and charging from said load to said power storage device to be performed; and

detection means for detecting a decrease in insulation resistance of the power supply device,

said detection means, when said load is connected to said electric power conversion device, setting a determination threshold value for detecting the decrease in said insulation resistance to a value lower than the determination threshold value in a non-connected state of said load to said electric power conversion device.

2. The power supply device according to claim 1, wherein the determination threshold value when said load is connected to said electric power conversion device is determined based on a capacitance of said load.

3. The power supply device according to claim 1, wherein when said load is connected to said electric power conversion device, said detection means sets a determination period for defining the decrease in said insulation resistance to a period shorter than the determination period in the non-connected state.

4. The power supply device according to claim 1, further comprising means for shutting down a system of said electrically-driven vehicle when the decrease in said insulation resistance is detected in a case where said load is connected to said electric power conversion device.

5. The power supply device according to claim 1, wherein said load includes a line-bypass capacitor connected between ground and a power line pair connected to said electric power conversion device.

6. The power supply device according to claim 1, wherein said detection means includes

a resistance element having a predetermined resistance value,

a voltage generating device connected between said resistance element and vehicle ground and generating a voltage having a predetermined frequency,

a capacitive element connected between said resistance element and an electric power line of the power supply device,

a voltage detection device detecting a voltage between said resistance element and said capacitive element,

a setting unit setting said determination threshold value, and

a determination unit determining that said insulation resistance decreases, based on the voltage detected by said voltage detection device and the determination threshold value set by said setting unit.

7. The power supply device according to claim 1, wherein said electric power conversion device includes

first and second AC electric motors each having a star-connected polyphase winding as a stator winding,

first and second inverters provided corresponding to said first and second AC electric motors, respectively, and transmitting and receiving electric power to and from said power storage device,

an inverter control device controlling said first and second inverters, and

a connecting device for connecting said load to a neutral point of said polyphase winding when one of power feeding from said power storage device to said load and charging from said load to said power storage device is performed.

8. An electrically-driven vehicle incorporating the power supply device according to claim 1.

13. An electrically-driven vehicle incorporating the power supply device according to claim 2.

14. An electrically-driven vehicle incorporating the power supply device according to claim 3.

15. An electrically-driven vehicle incorporating the power supply device according to claim 4.

16. An electrically-driven vehicle incorporating the power supply device according to claim 5.

17. An electrically-driven vehicle incorporating the power supply device according to claim 6.

18. An electrically-driven vehicle incorporating the power supply device according to claim 7.

9. A method of controlling a power supply device incorporated in an electrically-driven vehicle,

said power supply device including

a power storage device,

an electric power conversion device configured to allow at least one of power feeding from said power storage device to a load external to the vehicle and charging from said load to said power storage device to be performed, and

a detection device detecting a decrease in insulation resistance of the power supply device,

said control method comprising:

a first step of determining whether or not said load is connected to said electric power conversion device; and

a second step of, when it is determined that said load is connected to said electric power conversion device, setting a determination threshold value for detecting the decrease in said insulation resistance to a value lower than the determination threshold value in a non-connected state of said load to said electric power conversion device.

10. The control method of the power supply device according to claim 9, wherein the determination threshold value when said load is connected to said electric power conversion device is determined based on a capacitance of said load.

11. The control method of the power supply device according to claim 9, further comprising a third step of, when it is determined that said load is connected to said electric power conversion device, setting a determination period for defining the decrease in said insulation resistance to a period shorter than the determination period in the non-connected state.

12. The control method of the power supply device according to claim 9, further comprising a fourth step of, when said detection device detects the decrease in said insulation resistance in a case where said load is connected to said electric power conversion device, shutting down a system of said electrically-driven vehicle.