A high-efficiency sepic soft-switching converter and its control method

Abstract

The invention relates to a high-efficiency Sepic soft-switching converter and its control method. On the basis of the basic Sepic circuit, a passive zero-ripple circuit, an active clamping circuit and a voltage doubler unit are introduced; the invention retains the input current of the Sepic converter Continuous characteristics, introducing a passive ripple circuit, through the series combination of coupled inductors and inductors and capacitors, the circuit is connected in parallel on the input side to achieve the zero-ripple effect of the input current, and realize the zero-ripple function of the input current, and it has nothing to do with the duty cycle. It has nothing to do with the relationship between the leakage inductance and the excitation inductance when the coupled inductance transforms the transformer, and has the characteristics of simple structure and high reliability. The active switches of the present invention all realize zero-voltage conduction, which reduces the loss caused by the switching tube, and realizes zero-voltage switching based on the Sepic converter for the first time; the use of leakage inductance, the diodes all realize zero-current turn-off, which reduces the reverse recovery loss; the voltage stress of the switching tubes is much lower than the output voltage, and low withstand voltage switching tubes can be used to improve the efficiency of the converter.

Description

technical field [0001] The invention relates to the technical field of converters, in particular to a high-efficiency Sepic soft-switching converter and a control method thereof. Background technique [0002] According to the latest data and predictions from the IEA: the world's primary energy consumption is growing at an average annual rate of 1.6%, traditional non-renewable energy is in short supply, and the energy crisis is serious. New energy such as photovoltaics, fuel cells, and wind power has become an important research topic in the world. Research on high-gain DC-DC converters in uninterruptible power supplies, photovoltaic power generation and fuel cell power generation systems has become one of the hotspots in the field of power electronics. [0003] Domestic and foreign researchers mainly proposed the following types of high-gain DC / DC converters: [0004] 1) Cascaded DC / DC converter, the output of the front stage of the converter is used as the input of the lat...

AI Technical Summary

Problems solved by technology

[0009] Aiming at problems such as low voltage gain of traditional converters, switches working in a hard state, and input ripples, the present invention provides a high-efficiency Sepic soft switching converter and its control method. The ripple circuit realizes the high gain of the converter, realizes the zero-voltage turn-on of the switch, and the effect that the input current ripple is zero

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