Transformer leakage inductance energy absorption and feedback method

Abstract

The invention provides a transformer leakage inductance energy absorption and feedback method. According to the method, PGND and Vin are included, a C0 is electrically connected between the PGND and the Vin; two ends of the C0 are connected with a transformer in parallel; an input circuit of the transformer is connected with a main switch tube Q1 in series, an input circuit of the transformer is provided with a Lleak (transformer parasitic leakage inductance), an output end of the transformer is electrically connected with an SGND, the output end of the transformer is also electrically connected with a Vo, and a D1 is connected between the Vo and the transformer in series. The transformer leakage inductance energy absorption and feedback method provided by the invention has the advantagesthat a simpler circuit design is adopted; compared with an RCD absorption scheme which is widely applied, only several components are added, but the peak voltage on a main switch tube can be reduced by 60%-90%, the full-load efficiency is improved by 0.5%-1%, and the energy conservation and emission reduction effects are very obvious; and compared with active clamping absorption, the design is simple, and expensive and complex special control chips and circuits are not needed.

Description

technical field [0001] The invention relates to the technical field of transformer application, in particular to a transformer leakage inductance energy absorption and feedback method. Background technique [0002] Taking the flyback topology as an example, the leakage inductance energy stored on the primary winding of the transformer will generate a large peak voltage at both ends of the switch tube when the switch tube is turned off, causing overvoltage stress and reducing the conversion efficiency of the whole machine , so in practical applications, it is necessary to use the absorption feedback circuit to absorb or feed back the leakage inductance energy to the input or output of the power supply. The commonly used absorption feedback circuits are: RC absorption, RCD absorption, third winding absorption, active clamping Wait. [0003] Both RC and RCD absorption belong to lossy absorption. RC absorption is the simplest, but the absorption effect is very general. It is su...

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Problems solved by technology

[0008] The invention provides a transformer leakage inductance energy absorption and feedback metho

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