Soft switch resonance DC converter reducing voltage stress of diode and calculation method

Abstract

The invention discloses a soft switch resonance DC converter reducing the voltage stress of a diode. The soft switch resonance DC converter absorbs a part of leakage inductance of a transformer and takes the part as a resonance inductance, and absorbs a junction capacitance of a switch tube and a junction capacitance of the diode and takes the absorbed junction capacitance as part of the resonanceinductance. The related converter can realize zero-voltage switching ON / OFF of a switch tube and the diode and zero-current switching OFF of the diode, the switching loss of the converter is almost 0, the efficiency of the converter is improved, the voltage stress of the diode is clamped to two times of the output voltage, and the voltage stress is reduced.

Description

technical field [0001] The invention relates to a technology of a resonant converter, in particular to a soft-switching resonant DC converter and a method for reducing diode voltage stress. Background technique [0002] Increasing the switching frequency of the converter is an effective means to increase its power density, but for hard switching circuits, increasing the switching frequency means increasing the switching loss, which will greatly reduce the overall efficiency of the converter. Therefore, it is very important to study the soft switching technology, that is, to increase the switching frequency of the converter without increasing the switching loss. [0003] Resonant technology is an important means to realize soft switching. Since most of the commonly used switching tubes currently use MOSFETs, it is a common method to use their body diodes to realize zero-voltage switching, such as LLC resonant converters, phase-shifted full-bridge converters, and so on. Howe...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a soft-switching resonant DC converter and a voltage gain calculation method for reducing the voltage stress of the diode, which realizes the zero-voltage switching of the switch tube and the diode and the zero-current shutdown of the diode, and the switching loss of the converter is almost Zero, improving the efficiency of the converter, solving the technical problem that the zero-voltage switching quasi-resonant converter can only improve the switching conditions of one device in the switching tube and diode, and the voltage stress of the zero-voltage switching multi-resonant converter is too large

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