Research For High-efficiency Micro-inverters In Grid-connected PV Systems

In recent years,due to the impact of the world’s energy crisis,the use of renewable energy has been rapidly promoted,especially, pohotovoltaic power generation has made a considerable progress,and becomes one of the mainstream of new energy utilization.With the continuous improvement of photovoltaic cell materials and power electronics technology,photovoltaic grid-connected system continues to develop its high efficiency,high power density,high reliability and low cost,and has made great results.In the photovoltaic grid-connected power generation systems,due to its unique advantages as its small size, high efficiency,safety,low cost and easy to extend,micro-photovoltaic power generation system has become a trend of photovoltaic power generation system. So,the article summarizes the common topologys of the micro-photovoltaic system and their respective advantages and disadvantages.by comparision and analysis,it proposes to use a novel topological structure,which is series resonant push-pull voltage high frequency linkmicro-inverter, and anlayzes its working principle in detail and makes it be the prototype of the system topology. Through detailed analyzing its feasible MPPT control machine network control strategies, this paper proposes a closed-loop control mode.According to the above theoretical analysis, it makes parameter settings on the200W series resonant push-pullvoltage-frequency link micro-inverter prototypefor,and gives a detailed analysis on its main components.Then,by using the Pspice software and Matlab,it simulates on pre-series resonant and the overallsystem simulation.And this paper also designs hardware circuits for prototype,by creating a experimental platform for micro-inverter system, it tests a physical verification on system.