The Study And Design Of Solar Gird Micro-inverter Based On Single-stage Flyback Structure

Solar energy,being equipped with four superiorities of durable supply,clean,huge reserves and convenient application,make the energy consumption structure and the amount of new energy investment gradually tilted to the photovoltaic technology.This also implies that the photovoltaic technology is likely to become a breakthrough in China's energy problems.The research work was financially supported by the "2011" Hubei Collaborative Innovation projects.Based on the project team previous studies,studied and developed a solar gird micro-inverter.The main works are presented as follows:Firstly,according to function requirements and the design scheme,this thesis analyzed the each module function of the main circuit,completed the calculation and selection of component parameters in each module,including the choice of the decoupling capacitor,the design of the flyback,the design of the active clamp circuit,and the design of the frequency converter.Then,on the basis of the main circuit,this thesis completed the design of the detection circuit.Secondly,based on the hardware parameters,this thesis analyzed the average equivalent circuit of grid connected flyback converter,established the small-signal AC model,calculated the ideal PI parameters,and verified the parameters correctness by simulation.The model can help to get the ideal current loop PI controller parameters,shorten the development cycle,and lay the foundation for the improvement and optimization of the device.Thirdly,contraposed the disadvantage of the traditional PLL method,this thesis presented a software PLL method based on dp rotating coordinate system,established the mathematical model,combined with C language and MATLAB,verified the tracking effect of the method by simulation.Fourthly,according to the above analysis,this thesis established the model of circuit simulation.Then,based on the design and simulation,established a 300 W single-stage flyback solar grid micro-inverter to verified the rationality of the research and design by the test results.