Flyback converter circuit of series active clamp

Abstract

The invention provides a flyback converter circuit of a series active clamp. The circuit comprises a primary main power loop unit, a clamping loop unit and a secondary rectifying and filtering unit. The primary main power loop unitcomprises an input energy storage filter capacitor, a clamping capacitor, a transformer and a main power switch tube, one end of the clamping capacitor is connected with a positive terminal of voltage input, the other end of the clamping capacitor is connected with a synonym terminal of the transformer, a dotted terminal of the transformer is connected with a drain electrode of the main power switch tube, and a source electrode of the main power switch tube is connected with a negative terminal of the voltage input; the clamping loop unit is used for transferring and storing the leakage inductance energy of the transformer into the clamping capacitor and feeding back part of the energy into the transformer to be transmitted to a secondary winding; and the secondary rectifying and filtering unit rectifies pulsating voltage on the secondary winding into direct-current voltage to provide energy for an output load when the transformer is subjected to reverse excitation. According to the invention, the number of turns of the windings needed by excitation inductance can be reduced, meanwhile, drain-source voltage on the main power switch tube is also reduced, switching loss of the main power switch tube is reduced, and the circuit conversion efficiency is improved.

Description

Technical field [0001] The present invention relates to the field of switching power converters, in particular, it relates to a flyback converter circuit of a tandem-type active clamp. Background technique [0002] Flyback switching power supply because of its simple circuit structure, device required less, low cost, etc. are widely used. However, since the conventional flyback switching power supply circuit is an RCD clamp absorption, the absorption circuit converts the transformer leakage inductance energy into heat is consumed, thus limiting the efficiency. At the same time the power supply to the high power density, small size and lightweight trend, needs to raise the switching frequency in order to reduce the volume of the transformer and passive components, conventional flyback switching power supply is a hard switch, raise the switching frequency would pose switch losses increase, reduce product efficiency. [0003] To solve the problem of the conventional flyback switchin...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a series active clamp flyback converter circuit, which can effectively solve the pressure problem of the power switch tube and improve the conversion efficiency of the circuit

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