Push-pull - flexible switching converter with serial-connected resonance unit

Abstract

The invention discloses a push-pull flexible switching converter with a serial-connected resonance unit, wherein the converter comprises a primary push-pull circuit, an isolation transformer, a secondary rectification circuit and an output circuit. The LC resonance unit is connected in series between the isolation transformer and the secondary rectification circuit; and proper charging / discharging capacitance values of a power switch tube of the primary push-pull circuit and proper inductance and capacitance values of the LC resonance unit are set, so that the converter works in a flexible switching state, the power switch tube is switched on with zero voltage and switched off with zero current, and the disconnection peak of a secondary-side rectification unit can be eliminated. Thus, the conversion efficiency is improved, switching noises are reduced, and the converter can be lightened. The converter of the invention is simple in structure, the size of the resonance unit in the converter is small, and the converter can be lightened; the conversion efficiency is higher than that of a traditional converter; and the switching noises due to switching operation can be eliminated, and the electromagnetic compatibility of the converter can be improved.

Description

technical field [0001] The invention relates to the technical field of power electronics conversion, in particular to a push-pull switching converter. Background technique [0002] At present, the push-pull topology converter is widely used due to its own characteristics, especially in the occasion of low voltage input and high voltage output. With the development of power electronics technology, there are requirements for miniaturization, light weight and high efficiency of power supply products. In the push-pull converter, filter inductors, capacitors and transformers account for a large proportion of volume and weight. Reducing the volume and weight of these components is the main way to miniaturize and reduce weight. In the push-pull converter circuit, increasing the switching frequency can correspondingly increase the cut-off frequency of the filter, so that smaller inductors and capacitors can be selected to reduce the volume and weight of the filter; increasing the s...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problems of the existing push-pull circuit, such as increased switching loss caused by increasing the switching frequency, aggravated diode reverse recovery, decreased circuit efficiency and electromagnetic interference, and provides a simple, lightweight, switching converter Push-pull converter with high efficiency and low electromagnetic interference

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