A Full-Bridge Soft-Switching DC Converter

Abstract

The invention discloses a full-bridge soft-switching DC converter, which includes a transformer primary circuit and a transformer secondary circuit. The primary circuit includes an input power supply, first to fourth switch tubes, and an isolation transformer primary winding; wherein the first The first switch tube and the third switch tube, the second switch tube and the fourth switch tube respectively form two half-bridge circuits, and the two ends of the two half-bridge circuits are respectively connected to the positive pole and the negative pole of the input power supply, and the primary side of the isolation transformer The two ends of the winding are respectively connected to the middle points of the two half-bridge circuits; the first and second clamping switch tubes are sequentially connected in series between the two bridge arms of the two half-bridge circuits. In the present invention, by using the synchronous rectification driving signal of the secondary side to control the switching time of the two auxiliary switching tubes of the full-bridge converter, the collected leakage inductance energy of the primary-side transformer can be released within the dead time, and the full-bridge converter main The ZVS soft switching of the switching tube has low EMI interference and high efficiency.

Description

technical field [0001] The invention relates to a full-bridge soft-switching high-efficiency electric energy conversion device, in particular to a medium and small power direct current converter applied to low output voltage and high output current occasions. Background technique [0002] In order to reduce the size of the switching converter, the trend of high frequency switching power supply is becoming more and more obvious. However, when the switching speed increases, the loss of the power switch tube device increases sharply, which not only brings about problems such as EMI and thermal stress, but also reduces the reliability of the converter itself. In order to improve the switching frequency and reduce the switching loss, the soft switching technology of ZVS and ZCS has become the mainstream technology of switching power supply, and has greatly improved the working efficiency of switching power supply. The traditional soft-switching technology of phase-shifted full-b...

AI Technical Summary

Problems solved by technology

The traditional soft-switching technology of phase-shifted full-bridge converter needs to add additional resonant inductance or resonant capacitor, but this method will not only increase the size and complexity of the converter, but also increase the stress of power devices sharply, resulting in a loss of duty cycle. Serious and other shortcomings; asymmetrical full bridge and LLC converters have relatively harsh soft switching conditions, and are not suitable for occasions where the input operating voltage is wide

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