Synchronous rectification control method and device for phase-shifted full-bridge/push-pull bidirectional converter

Abstract

The invention relates to a synchronous rectification control method and device for a phase-shifting full-bridge / push-pull bidirectional converter, which belongs to the technical field of converter rectification control, and solves the drive mode of taking or logic of a full-bridge phase-shifting drive signal in the prior art The problem of low light load efficiency caused by buck mode. The primary side circuit of the bidirectional converter includes the super forearm upper bridge arm switch S 1 , Super forearm lower arm switch S 3 , Lagging arm upper bridge arm switch S 2 , switch S of the lower arm of the lagging arm 4 ; The secondary circuit includes: a first synchronous rectification switch SR connected to the opposite end of the secondary winding 1 , the second synchronous rectification switch SR connected to the same terminal of the secondary winding 2 ; The method includes: when the bidirectional converter works in the step-down mode, the receiving switch S 1 ‑S 4 drive level, the switch S 1 with switch S 4 The drive level is taken and logical operation, and the switch SR is generated 1 drive level; for switch S 2 with switch S 3 The drive level is taken and logical operation, and the switch SR is generated 2 drive level. Improve the efficiency of the converter under light load.

Description

technical field [0001] The invention relates to the technical field of converter rectification control, in particular to a synchronous rectification control method and device for a phase-shifted full-bridge / push-pull bidirectional converter. Background technique [0002] When using the phase-shifted full-bridge / push-pull bidirectional converter topology, when the bidirectional converter works in the step-down mode, the high-voltage side full-bridge switch works in the phase-shifted control mode, and the full-wave rectification on the low-voltage side is under greater load. The current stress of the rectification system can reduce the power loss of the rectification unit by using the synchronous rectification method. The traditional synchronous rectification method is usually driven by the full-bridge phase-shift drive signal or logic method, and is widely used in the full-bridge analog control chip. When the converter is under light load condition, excessive driving time wil...

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Problems solved by technology

[0003] In view of the above-mentioned analysis, the present invention aims to provide a synchronous rectification control method and device for a phase-shifted full-bridge / push-pull bidirectional converter, to solve the drive mode of taking or logic of the full-bridge phase-shifted drive signal in the prior art The problem of low light load efficiency caused by buck mode

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