Method of driving DC/DC converter, and DC/DC converter

• US 7,843,713 B2
• Filed: 12/18/2008
• Issued: 11/30/2010
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Sone, Toshihiro, Takenaka, Hidekazu
• Primary Examiner(s): Berhane; Adolf
• Assistant Examiner(s): PHAM, EMILY P
• Application Number:
  US12/338,399
• Publication Number:
  US 20090160265A1
• Time in Patent Office: 712 Days
• Field of Search: 323/222, 323/907, 363/132, 363/17, 363/98, 363/70, 363/15, 363/95, 363/97, 363/131
• US Class Current: 363/95
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

When the three U-, V-, W-phase arms of a DC/DC converter are turned on, they are alternately turned on by gate drive signals. When the U-, V-, W-phase arms are alternately turned on, an upper arm switching device of the U-phase arm, for example, is turned on, and thereafter a lower arm switching device of the U-phase arm is turned on. Thereafter, an upper arm switching device of the V-phase arm which is next to the U-phase arm is turned on, and thereafter a lower arm switching device of the V-phase arm is turned on. The upper and lower arm switching devices are thus turned on in a rotation switching process.

Claims

1. A method of driving a DC/DC converter capable of operating in a voltage increasing mode and a voltage reducing mode, the method comprising the steps of:

connecting a plurality of phase arms parallel to each other between a first electric power device and a second electric power device, each of the phase arms comprising a series-connected circuit of an upper arm switching device and a lower arm switching device and diodes connected inversely across the upper arm switching device and lower arm switching device;

alternately turning on the phase arms; and

when one of the phase arms is turned on, turning on either the upper arm switching device in one switching period in the voltage reducing mode, or the lower arm switching device in one switching period in the voltage increasing mode, the switching period being 2π

, or alternately turning on the upper arm switching device and the lower arm switching device once in one switching period in a transition between the voltage reducing mode and the voltage increasing mode, the switching period being 2π

.

2. A method according to claim 1, wherein when the phase arms are alternately turned on, the upper arm switching device and the lower arm switching device of one of the phase arms are alternately turned on, and thereafter the upper arm switching device and the lower arm switching device of a next one of the phase arms are alternately turned on.

3. A method according to claim 1, wherein when the phase arms are alternately turned on, the upper arm switching device of one of the phase arms is turned on, thereafter the lower arm switching device of the one of the phase arms is turned on, thereafter the upper arm switching device of a next one of the phase arms is turned on, and thereafter the lower arm switching device of the next one of the phase arms is turned on.

4. A method according to claim 1, wherein when the phase arms are alternately turned on, the phase arms are alternately turned on one in every switching period.

5. A method according to claim 1, wherein when the upper arm switching device and the lower arm switching device of one of the phase arms are alternately turned on, the upper arm switching device and the lower arm switching device are alternately turned on with a dead time interposed therebetween, and the phase arms are alternately turned on with a dead time interposed therebetween.

6. A method according to claim 1, further comprising the step of measuring temperatures of the upper arm switching devices and the lower arm switching devices;

and

when the phase arms are turned on, disabling those of the upper arm switching devices or the lower arm switching devices whose measured temperatures are higher than a threshold value.

7. A method according to claim 1, further comprising the step of inserting a single reactor between the first electric power device or the second electric power device and respective midpoints which connect the phase arms to each other, wherein the single reactor discharges and stores energy when the DC/DC converter converts a voltage between the first electric power device and the second electric power device.

8. A method according to claim 1, wherein the phase arms comprise three phase arms, and the six upper and lower arm switching devices of the three phase arms are fixedly mounted on a single heat radiation plate.

9. A DC/DC converter capable of operating in a voltage increasing mode and a voltage reducing mode comprising:

a first electric power device;

a second electric power device;

a plurality of phase arms connected parallel to each other between the first electric power device and the second electric power device, each of the phase arms comprising a series-connected circuit of an upper arm switching device and a lower arm switching device and diodes connected inversely across the upper arm switching device and the lower arm switching device, the phase arms having respective midpoints connected to each other;

a reactor inserted between the connected midpoints and the first electric power device or the second electric power device; and

a controller programmed to control the phase arms to turn on one at a time every switching period, the controller outputting a drive signal for turning on either the upper arm switching device in one switching period in the voltage reducing mode, or the lower arm switching device in the voltage increasing mode in one switching period, the switching period being 2π

, or alternately turning on the upper arm switching device and the lower arm switching device in a transition between the voltage reducing mode and the voltage increasing mode once in one switching period, the switching period being 2π

.