Dc-dc converter

• US 20070070655A1
• Filed: 11/24/2004
• Published: 03/29/2007
• Est. Priority Date: 12/11/2003
• Status: Abandoned Application

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Eguchi, Hiroyuki, Shimizu, Motohiro
• Application Number:
  US10/581,916
• Publication Number:
  US 20070070655A1
• Time in Patent Office: Days
• US Class Current: 363/17
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 1/40 Means for preventing magnetic saturation
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

To provide a DC-DC converter allowing miniaturization of a voltage transformer without fear of reducing conversion efficiency due to saturation of the transformer and allowing enhancement of conversion efficiency by suppressing switching loss. An LC resonance circuit 3 is inserted on the secondary side of a transformer 1. When driving means 4 alternately turn on and off a pair of switching means 2-1, 2-2, an output is obtained on the secondary side via the transformer 1. A current transformer 5 for current detection, a current value detection portion 6 and a current value comparison portion 7 detect a difference between each resonance current value per half cycle due to the operation of the LC resonance circuit 3. In response to its result, the drive means 4 regulate automatically on-state duty ratio of the switching means 2-1, 2-2 so as to align the resonance current values per half cycle.

Claims

1. A DC-DC converter comprising:

a transformer having primary side terminals, secondary side terminals, a primary side winding, and a secondary side winding and determining a voltage converting ratio;

a pair of switching means which is interposed between said primary side terminals and said primary side winding,

a LC resonant circuit comprised of a resonating reactor connected in series with said pair of switching means, and a resonating capacitor that resonates with said resonating reactor; and

a driving means for alternately turning said pair of switching means ON/OFF, wherein;

a resonant current detecting means for detecting a resonant current caused by an operation of said LC resonant circuit and means for feeding a detected output of said resonant current detecting means back to said driving means are provided; and

said driving means drives said pair of switching means by correcting their on-state lapses of time so that their on-state resonant currents may be nearly equal to each other based on the detected output of said resonant current detecting means.

2. The DC-DC converter according to claim 1, wherein said resonant current detecting means is provided on the primary side of said transformer.

3. A bi-directional DC-DC converter comprising:

a transformer having low-voltage side terminals, high-voltage side terminals, a low-voltage side winding, and a high-voltage side winding and determining a voltage converting ratio;

a low-voltage side pair of switching means interposed between said low-voltage side terminals and said low-voltage side winding;

a high-voltage side pair of switching means interposed between said high-voltage side terminals and said high-voltage side winding;

a low-voltage side rectifying element connected in parallel with each of switching elements in said low-voltage side pair of switching means;

a high-voltage side rectifying element connected in parallel with each of switching elements in said high-voltage side pair of switching means; and

a driving means for turning ON/OFF the switching elements in said low-voltage side pair of switching means and the switching elements in said high-voltage side pair of switching means, wherein;

a LC resonant circuit is interposed between said high-voltage side winding and said high-voltage side pair of switching means or between said low-voltage side winding and said low-voltage side pair of switching means;

a resonant current detecting means for detecting a resonant current caused by an operation of said LC resonant circuit and means for feeding a detected output of said resonant current detecting means back to said driving means are provided; and

said driving means drives said low-voltage side pair of switching means or said high-voltage side pair of switching means by correcting their on-state lapses of time so that their on-state resonant currents may be nearly equal to each other based on the detected output of said resonant current detecting means.

4. The DC-DC converter according to claim 3, wherein said LC resonant circuit is interposed between said high-voltage side winding and said high-voltage pair of switching means.

5. The DC-DC converter according to claim 3, wherein said low-voltage side pair of switching means and said high-voltage pair of switching means are each configured by interconnecting four switching elements in a bridge.