Full-bridge zero-voltage boost switching resonant converter based on LLC used for UPS

Abstract

The invention discloses a full-bridge zero-voltage boost switching resonant converter based on LLC used for UPS. The converter is characterized in that resonant converting circuit in DC / DC convertingmodule is full-bridge LLC resonant converting circuit and the converting circuit comprises switch bridge which is composed of four main switching tubes through full-bridge connection, main transformerof which primary winding is in parallel with excited inductor, series resonance inductors connected with the main transformer, series resonance capacitors, and LLC resonance network composed of excited inductor, series resonance inductors and series resonance capacitors, wherein the network is connected with the two output ends of the switch full-bridge, and output sides of the main transformer is synchronous full wave rectifying circuit composed of two groups of rectifying diodes and are separately connected with two output capacitors sharing the same ground wire. The full-bridge zero-voltage boost switching resonant converter of the invention overcomes the defect that switch tube zero-voltage conduction in full scope is hard to realize, the work is easy to reach optimal state, the testvalue of the practical boosting circuit efficiency is about 95%, the volume of electromagnetic elements is reduced, the circuit is simplified and the cost is reduced.

Description

technical field [0001] The present invention relates to a full-bridge circuit, in particular to an LLC-based full-bridge zero-voltage switch step-up resonant converter for UPS. Background technique [0002] Most of the existing low-power battery mode circuits for UPS use push-pull circuits, half-bridge circuits, full-bridge circuits, etc. plus inverter circuits to form the main circuit topology. The efficiency of the whole machine is generally 83% to 87%, and the cost is relatively high. , DC / DC circuit frequency is generally 40khz ~ 50khz. Due to the large resonance Q value of the half-bridge LLC boost resonant converter, the monotonicity of the voltage decrease with the increase of the frequency is very poor, and it is difficult to realize the zero-voltage conduction (ZVS) of the switching tube in the whole range, which has become a half-bridge circuit design. Difficulties in. The primary power supply using the LLC full-bridge DC / DC circuit has a DC / DC circuit efficiency...

AI Technical Summary

Problems solved by technology

However, if the above technologies are used in UPS products at the same time, LLC needs to be applied to the booster circuit with dual busbar output, and no similar circuit has been reported so far.

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