POWER SUPPLY DEVICE

• US 20080185999A1
• Filed: 02/05/2008
• Published: 08/07/2008
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Original Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Inventors: MIZOGUCHI, Tetsuya, BULLOCK, Duncan, MATSUKAWA, Yasushi
• Granted Patent: US 8,432,058 B2
• Time in Patent Office: Days
• US Class Current: 320/166
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power supply device that enables completion of precharging to be accurately determined without increasing manufacturing cost. The power supply device includes a battery pack, a positive main contactor, a precharge contactor, and a precharge resistor. The battery pack supplies DC power to an inverter. A smoothing capacitor is arranged between input terminals of the inverter. The positive main contact disconnects the inverter from a positive electrode of the battery pack. A voltmeter detects the voltage between a negative electrode of the battery pack and a connection node of the precharge contactor and precharge resistor. Voltage detection values taken by the voltmeter immediately before precharging and during precharging are used to determine precharging completion.

Claims

1. A power supply device comprising:

a load including a smoothing capacitor used for precharging;

a direct current power supply which supplies direct current power to the load and which includes a first electrode and a second electrode;

a main contactor arranged between the load and the first electrode of the direct current power supply;

a precharge contactor connected in parallel to the main contactor;

a precharge resistor connected in parallel to the main contactor and in series to the precharge contactor between the direct current power source and the precharge contactor, wherein the smoothing capacitor undergoes precharging via the precharge resistor when the precharge contactor closes; and

a voltage detection unit which detects voltage between the second electrode of the direct current power supply and a connection node of the precharge contactor and the precharge resistor.

2. A power supply device according to claim 1, further comprising:

a determination unit which determines whether precharging has been completed based on a first voltage detection value detected by the voltage detection unit prior to precharging and a second voltage detection value detected by the voltage detection unit during precharging, wherein the determination unit determines that precharging has been completed when the second voltage detection value becomes greater than a determination value set in accordance with the first voltage detection value.

3. The power supply device according to claim 2, wherein the determination value is set to be higher as the first voltage detection value becomes higher.

4. The power supply device according to claim 2, wherein the first voltage detection value corresponds to a precharging saturation voltage, and the second voltage detection value is a precharge voltage applied to the smoothing capacitor.

5. The power supply device according to claim 2, wherein the determination value is obtained by subtracting a predetermined constant from the first voltage detection value.

6. The power supply device according to claim 2, wherein the determination value is obtained by multiplying the first voltage detection value by a constant that is less than one.

7. The power supply device according to claim 1, further comprising:

a determination unit which determines whether precharging has been completed based on a first voltage detection value detected by the voltage detection unit prior to precharging and a second voltage detection value detected by the voltage detection unit during precharging, wherein the determination unit determines that precharging has been completed when a difference between the first voltage detection value and the second voltage detection value becomes less than a predetermined determination value.

8. The power supply device according to claim 7, wherein the first voltage detection value corresponds to a precharging saturation voltage, and the second voltage detection value is a precharge voltage applied to the smoothing capacitor.

9. The power supply device according to claim 1, further comprising:

an inverter for converting the direct current power supplied from the direct current power supply into alternating current power, wherein the inverter is supplied as the load with power by the power supply device.

10. The power supply device according to claim 7, wherein:

the main contactor includes a first contact and a second contact that come into contact with each other when the main contactor is closed; and

the determination value is set at an upper limit value of the voltage between the first and second contacts that withstands fusing of the first and second contacts.

11. A method for controlling precharging performed by a power supply device, the power supply device including a load having a smoothing capacitor used for precharging, a direct current power supply for supplying power supply voltage to the load and having a first electrode and a second electrode, a main contactor arranged between the load and the first electrode of the direct current power supply, a precharge contactor connected in parallel to the main contactor, a precharge resistor connected in parallel to the main contactor and connected in series to the precharge contactor between the direct current power source and the precharge contactor, and a voltage detection unit connected between the second electrode of the direct current power supply and a connection node of the precharge contactor and the precharge resistor, the method comprising:

obtaining a first voltage detection value detected by the voltage detection unit in a state in which the precharge contactor is open;

obtaining a second voltage detection value detected by the voltage detection unit in a state in which the precharge contactor is closed; and

determining whether precharging has been completed based on the first voltage detection value and the second voltage detection value.

12. The method according to claim 11, wherein:

said obtaining a first voltage detection value includes obtaining a precharging saturation voltage that is in accordance with the power supply voltage of the direct current power supply; and

said obtaining a second voltage detection value includes obtaining a precharge voltage applied to the smoothing capacitor.

13. The method according to claim 11, further comprising:

setting a determination value in accordance with the first voltage detection value; and

completing precharging when the second voltage detection value becomes greater than the determination value.

14. The method according to claim 13, wherein said setting a determination value includes setting the determination value to be higher as the first voltage detection value becomes higher.

15. The method according to claim 13, wherein said setting a determination value includes setting the determination value by subtracting a predetermined constant from the first voltage detection value.

16. The method according to claim 13, wherein said setting a determination value includes setting the determination value by multiplying the first voltage detection value by a constant that is less than one.

17. The method according to claim 11, further comprising:

calculating a difference between the first voltage detection value and the second voltage detection value; and

completing precharging when the difference becomes less than a predetermined determination value.

18. The method according to claim 17, wherein:

the main contactor includes a first contact and a second contact that come into contact with each other when closed;

the determination value is set at an upper limit value of the voltage between the first and second contacts that withstands fusing of the first and second contacts; and

said completing precharging includes completing precharging when the difference becomes less than the determination value that is set at the upper limit value.