High Gain Research On Buck-Boost-Cuk Integrated Converters With Coupled Inductor

In view of the increasingly serious environmental harm caused by the development and utilization of fossil energy,the focus of global demand for energy types is also changing.Now the leapfrog development from non renewable energy to renewable energy has been realized,which reflects the importance of environmental protection for the earth.Among them,solar energy as a relatively popular renewable energy has been favored by people.Relevant researchers have proposed a series of forms of power generation based on solar energy,Photovoltaic power generation is used broadly in the world,Since the DC/DC converter occupies a key position in the photovoltaic power generation process,people pay particular attention to it.Aiming at the problem that the voltage gain of a single converter is too low,In order to obtain high gain and ensure the continuity of the output current,First of all,a Buck-Boost converter and a Cuk Converter are proposed.the two converters are combined to obtain a combined Buck-Boost-Cuk Converter with parallel input and series output,On the basis of the combined converter,two kinds of extended structures are introduced,The correctness of the scheme was verified.However,the superposition of the extended structure will affect the performance of the converter.Then a Buck-Boost-Cuk Converter with coupled inductors is proposed.The voltage doubling unit of the new combined converter uses the coupled inductor secondary side and the diode capacitor branch to improve the gain;The former diode capacitor branch of the Cuk Converter is used as the clamping branch to limit the potential of the switch tube and reduce the stress of the switch tube.Afterwards,On this basis,a diode capacitor voltage doubling unit is added to form a double voltage structure to further enhance the gain,It has very flexible adjustability.The inductor current continuous mode and discontinuous mode of the two converters are analyzed respectively,and the critical conditions of inductor and the design parameters of the two converters are given.The advantages of the proposed converter are reflected through the performance comparison.In the end,The control parameters of PID module in MATLAB software of the two converters are substituted into the C-block module and combined with PSIM simulation software to obtain the output voltage in the closed loop state.Compared to open loop voltage,its fluctuation is smaller and tends to the stable value faster.It can not only determine the current waveforms of all equipment,but also clarify the corresponding stress conditions.Afterwards,the experimental prototype design was carried out through the experimental platform,and the correctness of the theory was compared and verified based on the comparison and analysis of the experimental results and the proposed theory.This paper contains 60 figures,6 tables and 54 references.