A Secondary-side Phase Shift Controlled Full-Bridge Converter

Abstract

A secondary side phase shift control full-bridge converter, belonging to the technical field of electric energy converters, including an inverter circuit, a high-frequency transformer, a rectifier network, a filter circuit and a load, wherein the rectifier network is composed of 4 diodes In the bridge rectifier circuit composed of D5 to D8, the present invention improves the rectifier network. The fifth switching tube S5 and the sixth switching tube S6 are respectively connected in series at the two output ends of the secondary side of the transformer. The present invention is suitable for high voltage, In high-power applications, soft switching of all switching tubes can be realized, which can effectively suppress the voltage and current peaks of the switching tubes, and the secondary side phase shift control of the transformer is used to realize that only the excitation current flows through the loop during the phase shifting process. The circulating current loss is reduced and the difficulty in realizing zero-voltage switching of the lagging bridge arm is solved.

Description

technical field [0001] The invention belongs to the technical field of electric energy converters, in particular to a secondary-side phase-shift control full-bridge converter. Background technique [0002] Converters composed of single tubes are generally used in small and medium power applications. In medium and high power applications, a full bridge converter is generally used. The traditional phase-shifted zero-voltage pulse-width modulation DC-to-DC (DC / DC) full-bridge converter uses the leakage inductance of the transformer or the primary side series inductance and the parasitic capacitance of the power tube to realize the zero-voltage switching of the switch tube. However, the topology of traditional circuits also has its own shortcomings. For example, the realization of zero-voltage soft switching of the switch tube on the primary side of the transformer is based on the large circulation loss. Although the loss of the switch tube is reduced, the increase in the circu...

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Problems solved by technology

[0005] The working principle of the present invention is: when the full-bridge converter is working, the same group of switch tubes (S1 / S4, S2 / S3) on the primary side of the high-frequency transformer are simultaneously triggered to be turned on, which is realized with the assistance of parallel capacitance and transformer leakage inductance resonance Zero voltage and zero current are closed, and the corresponding switch tubes (S6 and S5) on the secondary side of the transformer are not closed temporarily to complete the phase shift control, and the secondary side of the transformer is in an open state. At this time, only a small excitation current flows through the primary side of the transformer, greatly The circulating current loss during the phase shifting process is reduced, and the simultaneous triggering of the two switching tubes of the same bridge arm solves the problem of the difficulty in realizing the zero voltage switch of the lagging arm. When the current on the secondary side increases, the DC power supply outputs power to the load. When the same group of switches on the primary side is disconnected, the parallel capacitance and transformer leakage inductance are used to resonate to achieve zero-voltage shutdown.

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