Voltage multiplying synchronous rectifying multi-resonance soft switching converter

Abstract

The invention discloses a voltage doubling synchronous rectification multi-resonance soft switch converter circuit which comprises a resonant inductance L1, a resonant capacitance Cp1, an excitation inductance Lm, an auxiliary inductance L2, an auxiliary capacitance Cp2, current transformators CT1 and CT2 as well as synchronous rectifying tubes SR1 and SR2; and transformer secondary side adopts a voltage doubling synchronous rectification circuit. Based on the traditional LLC converter, the invention is added with the L2 and Cp2, so as to change the impedance characteristic of a resonant unit and introduce impedance pole. Impedance is increased rapidly near the pole frequency, so that the gain adjustment range is expanded, and the converter can adapt to voltage range application with wide input or output; and the voltage doubling synchronous rectification circuit can reduce the voltage stress. The invention has simple circuit structure, high efficiency, easy implementation, convenient use as well as practical value and economic benefit.

Description

technical field [0001] The invention relates to a voltage doubling synchronous rectification multi-resonant soft switching converter circuit. More precisely, the present invention relates to a five-element current resonance type soft switch and a current control synchronous rectification drive circuit converter suitable for voltage doubler rectification circuits. Background technique [0002] Traditional PWM chopper converters, whose power components work in hard switching mode, have large switching losses and low efficiency, and it is difficult to increase the power density through high frequency. At the same time, the EMI characteristics are poor, and many filter suppression units need to be added. Increased costs and reduced efficiency. [0003] The resonant converter uses a resonant circuit to create soft switching conditions for power components and reduce switching losses. In the resonant converter, a three-element LLC current resonant converter (see figure 1 ) is t...

AI Technical Summary

Problems solved by technology

[0004] Disadvantages of LLC converter: Since LLC has the best working efficiency only near the resonant frequency, the rated operating point is often set near the resonant efficiency point. Large gain; when the input voltage increases or the output voltage decreases, a lower gain is obtained by increasing the operating frequency

Considering that the junction capacitance between the transformer leakage inductance and the MOSFET drain-source will oscillate, causing voltage spikes, the voltage stress of the rectifier device will exceed the ideal voltage

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