Phase shift control method for full load range zvs of dual active full bridge bidirectional dc-dc converter

Abstract

The invention discloses a phase-shift control method for ZVS in the full load range of a dual-active full-bridge bidirectional DC-DC converter, which belongs to the field of high-frequency switching power supplies in the field of power electronics. The converter of the present invention introduces excitation current on the basis of the original topological structure, and compensates the minimum current required for resonance when the secondary side switching tube is turned off, thereby expanding the soft switching range of the secondary side switching tube of the transformer; the present invention operates in EPS mode Based on the injected excitation current, the control strategy of full load range ZVS and low current stress is designed. By controlling the duty cycle of the bridge on the high voltage side and the phase shift angle between the two full bridges, the converter can operate at different voltage ratios. Work in the ZVS region under different transmission powers to ensure the soft switching of the converter in the full load range, reduce the switching loss of the switch tube, reduce the current peak value, reduce the current stress of the power device, and reduce the on-state loss of the converter And circulation loss, further reducing circuit loss. The invention can improve the efficiency and reliability of the converter.

Description

technical field [0001] The invention relates to a phase-shift control method of ZVS in the full load range of a dual-active full-bridge bidirectional DC-DC converter, which belongs to the direction of high-frequency switching power supply in the field of power electronics. Background technique [0002] For power electronics applications that require two-way transmission of power, such as new energy power generation and energy storage batteries, there is a wide range of input and output voltages and load changes. For dual active full bridge bidirectional DC-DC converters, high transmission efficiency is a very important requirement. Zero-voltage switching (ZVS) of power devices can improve converter efficiency. For realizing zero-voltage soft switching, traditional phase-shift control is a very popular and simple control method. But there are some problems that need to be overcome. First of all, the current stress and return power of traditional phase-shift control are rel...

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Problems solved by technology

[0005] In order to overcome the problems that the dual active full bridge bidirectional DC-DC converter cannot realize soft switching in the full load range and the control strategy is complex when considering the junction capacitance, the full load of the dual active full bridge bidirectional DC-DC converter disclosed in the present invention The technical problem to be solved by the range ZVS phase-shift control method is: reduce the turn-on loss and transformer loss caused by current stress and return power, realize the full load range ZVS of the converter in a wide voltage range, and reduce the converter in any working condition. Lower the switching loss of the switching tube, improve the efficiency and reliability of the converter

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