DC POWER SUPPLY APPARATUS

• US 20120181990A1
• Filed: 01/12/2012
• Published: 07/19/2012
• Est. Priority Date: 01/19/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation, Nippon Soken, Inc.
• Original Assignee: DENSO Corporation, Nippon Soken, Inc.
• Inventors: ASAKURA, Fumio, OCHI, Kenji, YOSHIDA, Hiroshi
• Granted Patent: US 9,083,197 B2
• Time in Patent Office: Days
• US Class Current: 320/137
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/20 characterised by converters located in the vehicle
• CPC Class Codes: B60L 53/30 Constructional details of charging stations
• CPC Class Codes: B60L 53/53 Batteries
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• 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 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A DC power supply apparatus includes a charging circuit, which charges a secondary battery of a vehicle from an AC power source device or a DC power source device. The charging circuit includes a non-insulating converter circuit and an insulating converter circuit. A breaker relay disconnects the AC power source device and the charging circuit in an initial charging period to supply a large charging current to the secondary battery by the non-insulating converter circuit. As a result, charging can be performed with high efficiency without the insulation transformer. The breaker relay connects the AC power source device and the charging circuit after the initial charging period. Only the insulating converter circuit supplies the charging current to the secondary battery. Thus, adverse effect of stray capacitance of a circuit of the vehicle can be eliminated.

Claims

1. A DC power supply apparatus for converting power supplied from a power source device including a commercial power line system and supplying DC power to a load device, the DC power supply apparatus comprising:

a conversion circuit configured to supply the DC power and including an insulating transformer, the conversion circuit being switchable to operate as a non-insulating converter circuit, in which an input and an output is not insulated by the insulating transformer, or as an insulating converter circuit, in which the input and the output are insulated by the insulating transformer; and

a breaker device for shutting off power supply from the commercial power line system to the non-insulating converter circuit, when the conversion circuit supplies the DC power by the non-insulating converter circuit.

2. The DC power supply apparatus according to claim 1, wherein:

the breaker device shuts off the power supply from the commercial power line system to the non-insulating converter circuit and allows the power supply only from the power source device other than the commercial power line system to the non-insulating converter circuit, when the conversion circuit supplies the DC power by the non-insulating converter circuit; and

the breaker device allows the power supply from the commercial power line system to the insulating converter circuit and allows only the insulating converter circuit to convert the power supplied from the commercial power line system, when the conversion circuit supplies the DC power by the insulating converter circuit.

3. The DC power supply apparatus according to claim 1, wherein:

the conversion circuit supplies the DC power by the non-insulating converter circuit, when a predetermined condition is satisfied; and

the conversion circuit supplies the DC power by only the insulating converter circuit, when the predetermined condition is not satisfied.

4. The DC power supply apparatus according to claim 3, wherein:

the conversion circuit is a charging circuit for charging the DC power to a secondary battery provided as the load device;

the predetermined condition is set based on a charging period for the secondary battery; and

the conversion circuit supplies the DC power by the non-insulating converter circuit in a former period of a charging period for the secondary battery, and supplies the DC power by the insulating converter circuit in a latter period of the charging period for the secondary battery.

5. The DC power supply apparatus according to claim 3, wherein:

the predetermined condition is set based on a magnitude of power supply capability of the power source device other than the commercial power line system;

the conversion circuit supplies the DC power by the non-insulating converter circuit when the power supply capability is higher than a predetermined threshold value, and supplies the DC power by the insulating converter circuit when the power supply capability is lower than the predetermined threshold value.

6. The DC power supply apparatus according to claim 1, wherein:

the conversion circuit includes the non-insulating converter circuit, the insulating converter circuit and a switching device for selectively connecting either one of the non-insulating converter circuit and the insulating converter circuit to the load device.

7. The DC power supply apparatus according to claim 6, wherein:

the switching device connects the non-insulating converter circuit and the insulating converter circuit to plural load devices exchangeably.

8. The DC power supply apparatus according to claim 1, wherein the conversion circuit includes:

a first full-bridge circuit provided at a primary side of the insulating transformer;

a second full-bridge circuit provided at a secondary side of the insulating transformer;

a switching device for connecting or disconnecting a primary terminal and a secondary terminal of the insulating transformer, and connecting and disconnecting a negative line of the first full-bridge circuit and a negative line of the second full-bridge circuit; and

a switchable converter circuit switchable to the non-insulating converter circuit or the insulating converter circuit by the switching device.

9. The DC power supply apparatus according to claim 8, wherein:

the non-insulating converter circuit is a step-up/down converter circuit, which is formed of an inductive component of the insulating transformer provided in a connected state of the switching device, the first full-bridge circuit and the second full-bridge circuit.

10. The DC power supply apparatus according to claim 2, wherein:

the conversion circuit supplies the DC power by the non-insulating converter circuit, when a predetermined condition is satisfied; and

the conversion circuit supplies the DC power by only the insulating converter circuit, when the predetermined condition is not satisfied.

11. The DC power supply apparatus according to claim 10, wherein:

the conversion circuit is a charging circuit for charging the DC power to a secondary battery provided as the load device;

the predetermined condition is set based on a charging period for the secondary battery; and

the conversion circuit supplies the DC power by the non-insulating converter circuit in a former period of a charging period for the secondary battery, and supplies the DC power by the insulating converter circuit in a latter period of the charging period for the secondary battery.

12. The DC power supply apparatus according to claim 10, wherein:

the predetermined condition is set based on a magnitude of power supply capability of the power source device other than the commercial power line system;

the conversion circuit supplies the DC power by the non-insulating converter circuit when the power supply capability is higher than a predetermined threshold value, and supplies the DC power by the insulating converter circuit when the power supply capability is lower than the predetermined threshold value.

13. The DC power supply apparatus according to claim 2, wherein:

the conversion circuit includes the non-insulating converter circuit, the insulating converter circuit and a switching device for selectively connecting either one of the non-insulating converter circuit and the insulating converter circuit to the load device.

14. The DC power supply apparatus according to claim 13, wherein:

the switching device connects the non-insulating converter circuit and the insulating converter circuit to plural load devices exchangeably.

15. The DC power supply apparatus according to claim 2, wherein the conversion circuit includes:

a first full-bridge circuit provided at a primary side of the insulating transformer;

a second full-bridge circuit provided at a secondary side of the insulating transformer;

a switching device for connecting or disconnecting a primary terminal and a secondary terminal of the insulating transformer, and connecting and disconnecting a negative line of the first full-bridge circuit and a negative line of the second full-bridge circuit; and

a switchable converter circuit switchable to the non-insulating converter circuit or the insulating converter circuit by the switching device.

16. The DC power supply apparatus according to claim 15, wherein:

the non-insulating converter circuit is a step-up/down converter circuit, which is formed of an inductive component of the insulating transformer provided in a connected state of the switching device, the first full-bridge circuit and the second full-bridge circuit.

17. The DC power supply apparatus according to claim 3, wherein:

the conversion circuit includes the non-insulating converter circuit, the insulating converter circuit and a switching device for selectively connecting either one of the non-insulating converter circuit and the insulating converter circuit to the load device.

18. The DC power supply apparatus according to claim 3, wherein the conversion circuit includes:

a first full-bridge circuit provided at a primary side of the insulating transformer;

a second full-bridge circuit provided at a secondary side of the insulating transformer;

a switching device for connecting or disconnecting a primary terminal and a secondary terminal of the insulating transformer, and connecting and disconnecting a negative line of the first full-bridge circuit and a negative line of the second full-bridge circuit; and

a switchable converter circuit switchable to the non-insulating converter circuit or the insulating converter circuit by the switching device.

19. A DC power supply method for supplying a secondary battery of a vehicle with DC power to charge the secondary battery by a conversion circuit, which includes an insulating transformer for insulating primary side and a secondary side thereof and converts power of a DC power source device and a commercial AC power source device, the DC power supply method comprising:

checking whether the secondary battery is to be charged;

setting the conversion circuit to operate as a non-insulating converter circuit, in which the insulating transformer is inoperative, when the secondary battery is determined to be charged;

disconnecting the non-insulating converter circuit and the AC power source device from each other, when the conversion circuit is set to operate as the non-insulating converter circuit,

charging the secondary battery initially by using only the DC power of the DC power source device by only the non-insulating converter circuit of the conversion circuit;

checking whether a predetermined switch-over condition is satisfied, the predetermined switch-over condition indicating that the secondary battery has been charged initially;

setting the conversion circuit to operate as an insulating converter circuit, in which the insulating transformer is operative, after the predetermined switch-over condition is satisfied;

connecting the insulating converter circuit and the AC power source device, when the conversion circuit is set to operate as the insulating converter circuit; and

charging the secondary battery by using only the insulating converter circuit of the conversion circuit.

20. The DC power supply method according to claim 19, further comprising:

connecting a primary terminal and a secondary terminal of the insulating transformer in a period of initial charging of the secondary battery so that the conversion circuit operates as the non-insulating converter circuit; and

disconnecting the primary terminal and the secondary terminal of the insulating transformer after the period of initial charging so that the conversion circuit operates as the insulating converter circuit.