Alternation parallel voltage-releasing type convertor implemented by three-winding coupling inductance

Abstract

A stagger parallel depressurizing transformer realized by three winding coupling inductances of the invention comprises two power switching tubes, two flywheel diodes, two clamping capacitances, an output capacitance and two coupling inductancess, and two coupling inductances respectively have three windings. The third winding of the two coupling inductances realizes the large step down ratio transformation, and the circuit composed of a first switch pipe and a first clamping capacitance adsorbs and transfers the leakage inductance energy of the first coupling inductances without loss, while the circuit composed of a second switch pipe and a second clamping capacitance adsorbs and transfers the leakage inductance energy of the second coupling inductances without loss, wherein the couplinginductance has the isolating function of the transformer and the filter inductance. The first winding and the third winding of the first coupling inductance, the leakage inductance of the first and the third windings of the second coupling inductance and first clamping capacitance, and the low pass filter composed of a second clamping capacitance reduce the input current ripple, with little circuit elements and simple structure, which realizes the large step down ratio transformation of the transformer and advanced efficiency of the transformer.

Description

technical field [0001] The invention relates to a DC-DC converter, in particular to an interleaved parallel step-down converter realized by three-winding coupled inductors. Background technique [0002] A conventional flyback (Flyback) interleaved parallel DC-DC converter includes two coupled inductors with two windings, two freewheeling diodes, two power switch tubes and an output capacitor, the first power switch tube The drain is connected to one end of the first winding of the first coupled inductor, the drain of the second power switch tube is connected to one end of the first winding of the second coupled inductor, and the other end of the first winding of the first coupled inductor is connected to the second The other end of the first winding of the coupled inductor is connected, one end of the second winding of the first coupled inductor is connected to the anode of the first diode, and one end of the second winding of the second coupled inductor is connected to the ...

AI Technical Summary

Problems solved by technology

This flyback type interleaved parallel DC-DC converter works with hard switching, and the switching loss is large, so it is not suitable for large step-down ratio conversion. The leakage inductance energy causes the voltage peak of the first power switch tube and the second power switch tube, and the efficiency is low. Low

Among other isolated step-down converters, the input current and output current ripple of the forward converter are large, and an additional circuit is required to realize the soft switching of the switching tube, and the full-bridge step-down converter requires more Switching tube, the cost is high, the current ripple of the traditional half-bridge step-down converter is relatively large, and it is only suitable for low-power occasions

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