Research On DC/DC Converter Technology With Low Input Current Ripple And High Voltage Gain

The intensification of the global energy crisis and the severe deterioration of the ecological environment have led to the application of clean and renewable energy such as photovoltaic panels and fuel cells to grid-connected power generation systems.However,photovoltaic panels and fuel cells have problems such as low output voltage and large fluctuation ranges.In practical applications,a step-up DC/DC converter needs to be connected in series at its output to achieve voltage matching.In addition,the output characteristics and life of these micro-sources are greatly affected by the input current ripple of the converter.Therefore,the converter is required to have a lower input current ripple while achieving high voltage gain conversion.The thesis first summarized the existing high-gain DC/DC converter topology construction technology,and systematically analyzed several methods to reduce the input current ripple of the converter,and compared their respective advantages and disadvantages.Secondly,it is observed that the traditional Sepic converter has the characteristics of current type input.Combining the coupled inductor and switched capacitor technology with it,a series of high gain DC/DC converters with current type input are proposed.This type of converter solves the traditional Sepic The shortcomings of the converter’s low voltage gain include the advantages of high voltage gain and continuous input current.The working principle and steady-state characteristics of one of the converters are discussed in detail,and the performances of the proposed converter and other high-gain Sepic converters are compared.Finally,a 200 W experimental prototype is made.The experimental results verify the theory.The correctness of the analysis.Subsequently,using the interleaved parallel technology,an asymmetrical interleaved parallel coupled inductive high-gain DC/DC converter constructed based on topological combination was proposed,and it was extended to N-phase.The steady-state working principle and the performance of various parameters of the converter are analyzed,and an experimental prototype is made for experimental verification.The experimental results verify the correctness of the theoretical analysis.Finally,combining the zero input current ripple Boost converter composed of a resonant ripple absorption circuit with coupled inductor technology,respectively,a zero input current ripple high gain DC based on a dual-winding coupled inductor voltage doubler unit and an integrated three-winding coupled inductor are proposed./DC converter.The proposed converters all have the advantages of zero input current ripple characteristics and high voltage gain.But the converter with integrated three-winding coupled inductor has higher voltage gain,and the voltage stress of the switch tube is lower.The working principle and steady-state characteristics of the two converters are analyzed in detail in the article,and a 500 W experimental prototype is built to verify the correctness of the theoretical analysis.