Research On High Gain Sepic Converter Based On Coupled Inductance Combination

In recent years,with the increasing demand for renewable energy,the proportion of electricity supply and demand of renewable energy,represented by light energy,in the energy structure is growing day by day.For distributed photovoltaic power generation system,in order to meet the higher voltage level of the post-stage grid-connection or transmission equipment,it is necessary to improve the voltage level through high-gain DC/DC converter.In order to improve the gain characteristics of the converter,the Sepic converter with good input characteristics is firstly used as the base and combined with capacitor-diode(D-C)branch.Through the combination of capacitor-inductor-diode-capacitor(C-L-D-C)and Double diode-capacitor(Double D-C)voltage doubling structure inside the converter,The feasibility of combined voltage doubling is proved by further increasing the gain of the converter.At the same time,in order to suppress the current impact,coupled inductance structure is introduced,and a new type of high gain coupled inductance combination Sepic converter is proposed.It retains the characteristic of continuous input current of Sepic converter and greatly improves the voltage gain.In order to reduce the voltage stress of the switch tube,the coupled inductance combination Sepic converter shares the diode-capacitor branch of Sepic structure to form a passive clamping absorption loop,which can effectively absorb the leakage inductance energy.The application of the combination idea to other basic converters is extended.Secondly,in the new type of high gain coupled inductor Sepic converter on the basis of the combination,to reduce the coupling inductance coils than N is too large window area is limited,further improve the voltage gain,added a set of diode capacitance voltage double branch,put forward with higher gain to add diode capacitance voltage double branch of coupled inductor Sepic converter.This article analyzes the working principle of the converter for Continuous induction and current continuity Mode,for the Continuous induction and current continuity Mode(DCM).The performance parameters of the converter and the boundary conditions of inductive continuous critical current mode(BCM mode)were deduced.The performance of the converter was compared with other high-gain SEPIC converters.The gain characteristics of the converter are further optimized,the problem of high voltage stress of the switch tube is improved,and the transformer parameters are designed.Finally,according to the overall parameter design of the converter,modeling,PID control and simulation verification of coupled inductance combination Sepic converter and coupled inductance Sepic converter with diode-capacitor voltage doubling branch are carried out through MATLAB and PSIM simulation software,and the experimental prototype is made according to theoretical analysis.Then an experimental platform was built to test the voltage and current waveforms of each link of the converter.The simulation results and experimental waveforms both verified the correctness of the theoretical analysis.The paper has 61 pictures,6 tables,and 58 references.