Switching sequence control method for a PS-ZVT bridge converter

• US 7,652,899 B2
• Filed: 05/30/2007
• Issued: 01/26/2010
• Est. Priority Date: 05/30/2007
• Status: Active Grant

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Mozipo, Aurelien T., Maple, Robert D.
• Primary Examiner(s): Sterrett; Jeffrey L
• Application Number:
  US11/807,718
• Publication Number:
  US 20080298087A1
• Time in Patent Office: 972 Days
• Field of Search: 363/17, 363/56.02, 363/98, 363/132
• US Class Current: 363/98
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/327 against abnormal temperatures
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/53873 with digital control
• CPC Class Codes: H02M 7/53878 by time shifting switching signals of one diagonal pair of the bridge with respect to the other diagonal pair
• 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

The switching sequence of a phase-shifted zero-voltage-transition (PS-ZVT) full bridge converter circuit is alternated between two modes by periodically reversing the switching sequence for diagonally opposed switching devices of the bridge. Over a period of operation, each of the switching devices periodically conduct the entire free-wheeling current that occurs during load current reversal transitions so as to balance their average power dissipation and reduce the overall power dissipation of the converter circuit.

Claims

1. A switching sequence control method for a phase-shifted zero-voltage-transition full bridge converter including switching devices arranged in first and second legs relative to a load circuit, the method comprising the step of:

alternately turning the switching devices on and off according to;

(1) a first switching sequence that results in zero voltage switch transitions but higher power dissipation in the switching devices of the first leg than in the switching devices of the second leg; and

(2) a second switching sequence that results in zero voltage switch transitions but higher power dissipation in the switching devices of the second leg than in the switching devices of the first leg;

thereby balancing the power dissipation in the first and second legs over a period of converter operation.

2. The switching sequence control method of claim 1, where:

alternating between the first and second switching sequences reverses an on/off switching pattern for diagonally opposed switching devices of the bridge converter.

3. The switching sequence control method of claim 1, including the steps of:

counting switching cycles at each switching sequence alternation; and

alternating between the first and second switching sequences when the switching cycle count reaches a predetermined value.

4. The switch sequence controller of claim 1, including the step of:

alternating between the first and second switching sequences so as to balance an average power dissipation in the switching devices and lower overall power dissipation of the bridge converter.

5. A switching sequence control method for a phase-shifted zero-voltage-transition full bridge converter including switching devices arranged in first and second legs relative to a load circuit, the method comprising the steps of:

turning the switching devices on and off according to a first switching sequence in which the switching devices of the first leg fully conduct a free-wheeling current that occurs during load current reversal transitions of the bridge converter; and

periodically changing from the first switching sequence to a second switching sequence in which the switching devices of the second leg fully conduct the free-wheeling current that occurs during load current reversal transitions of said bridge converter, thereby to balance a power dissipated by said switching devices during said load current reversal transitions and lower an overall power dissipation of the bridge converter.