Research On A New High Gain Sepic DC-DC Converter For Distributed Generation

With the progress of economic level and technology in recent years,new energy sources have been vigorously developed at home and abroad.Distributed power sources represented by new energy sources such as photovoltaic power generation,fuel cells,and small wind turbines have developed rapidly.Distributed power sources are mostly low-voltage direct current,and the voltage level is low during grid-connected power generation.Therefore,a high-gain DC converter is required to upgrade the low-voltage direct current to high-voltage direct current to supply power to the subsequent high-voltage direct current loads.Therefore,the DC converter with high voltage gain and high efficiency is one of the current research hotspots.In recent years,scholars and scientific research institutions from various countries have conducted a lot of research on high gain DC converters.This article first analyzes the working principle and main electrical performance of the traditional Sepic converter,active switched inductor Boost converter,and switched capacitor Boost converter.Fully combining the advantages of these three,the active switch inductor structure is substituted for the front-stage energy storage inductor of the traditional Sepic converter,and the switch capacitor structure is applied to the output end of the traditional Sepic converter to obtain a new high-gain Sepic converter.The magnetic integration technology is applied to the topology to form a new type of high-gain Sepic converter.The working mode of the converter is analyzed and the equivalent circuit diagram and main working waveform diagram of each mode are given.The expressions of the voltage gain and the voltage stress of the main components of the new high-gain Sepic converter are given,and the converter is also given.Parametric design guidelines.Theoretical analysis and simulation results show that the new high-gain Sepic converter has better electrical performance.While the voltage gain of the converter is greatly improved,the voltage stress of the main switch is smaller than the output voltage.In order to verify the correctness of theoretical analysis and simulation,this paper uses TMS320F28035 as the main control chip to build a 200 W experimental platform to verify the theoretical analysis.Firstly,perform PID control simulation on the converter to determine the PID control parameters;then design the sampling circuit,the switching tube drive circuit and the TMS320F28035 minimum system.Finally,the experimental verification is carried out according to the designed circuit,and the experimental results prove the correctness of the theoretical analysis of the article.The paper has 48 pictures,5 tables and 79 references.