The Study Of Non-isolated Single-phase Photovoltaic Grid-connected Inverter Based On DSP

With the constant development of the society, the demand for energy sources is increasingly urgent, however, traditional fossil energy stocks are limited and cause serious pollution to the environment, as a safe, efficient, pollution-free renewable energy, solar energy is paid with more and more attention. And the grid connected photovoltaic power generation technology is one of the most important parts, and has become one of the hot issue of researches. Based on the single phase two level grid connected photovoltaic inverter the research object, it does deeper analysis on maximum power point tracking, grid-connected control, hardware and software design. The main contents are:(1)Introduce the current situation and growing trend of domestic and international PV development, and elaborately introduce the classification of grid-connected PV power generation system, focuses on the analysis of the topological structure of photovoltaic grid connected inverter.(2)Introduce the principle and classification of photovoltaic cells, and give the mathematical model under the standard condition according to the equivalent model, and improve the analysis, put forward a kind of engineering mathematical model. Analyze and compare the high power point tracking control technologies, and the existing problems based on the traditional perturbation and observation method, an improved perturbation and observation method is proposed, the specific work flow chart is given.(3)Analyze the basic principle of grid-connected current control technology, briefly analyze and compare some of them. Then analyzes the dead beat control principle, and put forward the double closed loop current control technology based on power feed forward, the inner loop current of which adopts deadbeat control, and gives specific flow chart. Finally, introduce the control technology of the digital phase locked loop in photovoltaic grid-connected.(4)The relevant design of main circuit, sampling circuit and DSP control circuit of photovoltaic grid-connected inverter, and finally for the whole system, software part is designed. And the overall structure, main program and interrupt program of software flow chart is given.(5)Use PSIM software to simulation analysis of the photovoltaic battery、MPPT and dead-beat control.