Study On Zero Ripple High Gain DC/DC Converter Based On Coupled Inductor

Economic development is often inseparable from energy consumption.With the rapid development of the global economy,the energy crisis is becoming increasingly prominent,and the heavy use of traditional energy has caused a bad impact on the environment.The key to solving the energy crisis and environmental problems lies in vigorously developing clean and renewable energy.In recent years,new energy power generation systems based on solar energy and fuel cells have received widespread attention.However,the output voltage levels of photovoltaic panels and fuel cells are relatively low and cannot directly meet the requirements of the input side voltage level of the grid-connected inverter.Therefore,a DC/DC converter with higher voltage gain is required to convert the low voltage on the output side of new energy to the high voltage level required on the input side of the grid-connected inverter.Adding the coupled inductor to the traditional DC boost chopper circuit can effectively increase the voltage gain and improve the reverse recovery of the diode.Therefore,it is important to study the high-gain DC/DC converter with coupled inductor.The paper first introduces the research background of the subject and the current research status of high-gain DC/DC converters.At the same time,common methods for suppressing current ripple are given.Next,in order to improve the voltage gain of the converter and reduce the voltage stress of the device,on the basis of the basic coupled inductance type DC/DC converter,a coupled inductance type high-gain DC/DC converter with a double voltage unit is proposed.The working principle and performance of the converter are analyzed in detail,and the performance comparison with traditional Boost converter and basic coupled inductor voltage doubler DC/DC converter is given.It is concluded that the converter has the advantages of high voltage gain and low voltage stress of the switching device.Finally,the theoretical analysis is verified by experiments.Then,in order to reduce the input current ripple of the converter,on the basis of the above high-gain DC/DC converter,a coupled inductor ripple suppression unit and a passive zero ripple unit are introduced respectively.A zero-ripple high-gain DC/DC converter with coupled voltage-doubling unit and a passive zero-ripple high-gain DC/DC converter with double-voltage unit are proposed.They have different circuit structures.The working principle and static performance of the two converters are analyzed in detail,and the advantages and disadvantages of the two ripple suppressionmethods as well as the voltage gain and voltage stress of the two converters are compared.Finally,the correctness of the theoretical analysis is verified by MATLAB simulation and experiment.Finally,in order to further improve the power density of the converter,an improved three-winding zero-ripple high-gain DC/DC converter is proposed.The converter reduces the number of coupled inductors while retaining the characteristics of high gain,zero ripple and low voltage stress.So it has higher power density and lower circuit cost.Finally verify the feasibility of the circuit through experiments.There are 66 figures,7 tables and 81 references in this paper.