Research On Two-staged Photo Voleaic Of Micro Inverter

Solar power system has become an important trendacy in the development of new energy today, and research on the distributed photovoltaic (pv) power supply is an important branch of photovoltaic (pv) grid power generation research, a single-phase independent photovoltaic (pv) grid system of low power is suitable for families, cities with small range of applications because of conveniently and quickly, it also increasingly become a kind of the trend of the development of the photovoltaic (pv) of new energy, so the study of independent distributed power supply has very important significance. This article mainly to research on the two-staged photovoltaic (pv) research of micro inverter, to realize grid control high effciently, and summarizes the advantages and disadvantages of the system.To choose the main circuit topology is the important guarantee of realizing the photovoltaic (pv) grid micro inverter system. This paper designed two stage type inverter topology, former level using DC/DC booster transformation, the later level using high frequency flyback inverter with adopt isolation, finally the system feed into the grid by the whole bridge transformation, choosing the ways of inverter is the key of the photovoltaic system. Through detailing and comparing to the principle and control of two kinds of the flyback inverter circuit in this paper, finally determine the crisscross the flyback inverter circuit. Face to the problem of high frequency flyback input voltage, the article using the introduction of the active clamp soft switching circuit to reduces the loss and noise caused by high frequency switch. In this paper, the topology structure of each part has carried on the detailed introduction, and matches by the simulation experiments to verify the correctness of the topology structure, and finally use a control law of the common peak is suitable for the excitation system. Controlling of the flyback inverter by discontinuous current mode, and study of the double closed loop control to the whole system. Finally through the simulation software MATLAB and PSIM system with the method of combining the construction of the model. By comparing to the experimental results, it is concluded that the optimal solution, and verify the correctness of the theoretical model.Due to the input and output instantaneous power of the pv panels has a double frequency component, the component will lead to larger busbar voltage fluctuations, and it is seriously affected the final grid power quality. In order to solve this problem, this paper chose three power decoupling circuit to analysis and research, through the model building and simulation, the paper decided to selecting the two stage of power decoupling method by the simulation results of the output current waveform comparison, and this methord may to save the cost and made control process simplely, beside the resulting waveform of the circuit is the best, so selecting the final photovoltaic (pv) grid micro inverter topology.Finally, in this article, through the combination of MATLAB and CCS software design and the construction of the related hardware platform, with the experimental results show the feasibility of the system operation. It has high efficiency and can meet the requirement for the whole system, lays the foundation for the practical application of inverter.