A Design Of Micro-inverter For Photovoltaics

Under the background of the energy crisis and the guidance of policy subsidies,photovoltaic developed rapidly.With the increase of the installed capacity,the efficiency of the photovoltaic system and MPPT ability of the inverter are more and more demanding,witch effects the develop trend of inverters.Firstly,typical structures of the photovoltaic inverter are analysised,the advantages and development trends are summarized,and a classified summary of the market products and research status of the micro-inverter is made.Then,the development of push-pull converter are introduced.A soft switching push-pull converter is proposed,with magnetic integration to reduce duty ratio loss.The mathematical model of integrated magnetic elements is constructed and the working process of the circuit is analyzed.Subsequently,hardware design and software design were carried out.In terms of hardware design,the selection of components and parameter setting principles of main circuit,driving part and sampling part were summarized.As for the software design part,the overall control strategy is briefly analyzed,including maximum power point tracking,the phase-locked loop and grid-connected current control.Finally,the test platform was built,the MPPT effect,efficiency curve and power quality of the inverter prototype were tested,and the test results were given and analyzed accordingly.