Research On Micro Inverter Topology And Efficiency Characteristics

The traditional PV power system is the photovoltaic panel series, parallel connection bythe centralized inverter to convert DC into AC, this system leads to power generationefficiency that is not high and has hot spot issues because each battery plate exist differencesand shadow occlusion problems, in order to solve the above problem, each PV panel and aninverter is connected, so this can perform maximum power point tracking control for eachpanel, thus greatly improve the efficiency of the whole, this inverter power level is relativelylow, called micro inverter.This paper firstly introduces the application characteristics、performance requirementsand several key techniques of micro inverter, then comparative study of push-pull seriesresonant voltage type and push-pull current type, voltage and current of the flyback type, theflyback and push-pull structure in the power decoupling aspects are discussed, in order tosolve the topological problems, the interleaved flyback and bi-directional flyback type microinverter topology are put forward. And analysis of their advantages and disadvantages Thenthe method of improving efficiency of micro inverter is analyzed, introduces the applicationof soft switch technology and SiC power device,the calculation results prove the workingcondition of soft switch, then through the comparison of SiC and Si power devices loss, theSiC device can improve the efficiency.In the end, interleaved flyback structure and doubleflyback structure and SiC power device to replace the Si device was simulated by the Pspicesimulation software, the simulation results verify the theoretical.