Application Study Of Grid-connected PV System

Energy is the mother of the industry, its abundant or shortage, directly affecting the prosperity and depression of all trades and professions. Since the ancient times the energy plays a very important role to the development of human, and it is even more so to today’s international society. For our country, to speed up the development of economy, strengthen our country’s international social influence, energy security is indispensable. Today, mankind’s live traditional energy sources such as coal, oil decrease increasingly, and the development of renewable energy is imperative. In a variety of renewable energy, solar energy is one of the focus energy for Japan, the United States and other developed countries because it is inexhaustible, may develop the use of, and pollution-free. The use of solar energy including solar thermal and solar photovoltaic, and the application research of photovoltaic has been conducted in full swing.At present, photovoltaic technology has been widely concerned at home and abroad. Although the cost of solar power application system is still high currently, the associated technical studies should go ahead. Based on this background, on the basis of exploring the characteristics of photovoltaic cells and independent photovoltaic power generation system, the key of this paper is researching the main circuit topology structure, working principle and control method of the single phase photovoltaic grid-connected inverter. The main contents are as follows:(1)Analysis of the classification of photovoltaic power generation system and various features, focus on the analysis of solar array output characteristics;(2)Based on the output characteristics of solar array, this paper designed the DC-DC converter circuit, achieved the maximum power tracking of the solar array by using incremental conductance algorithms, and simulated in MATLAB;(3)Grid-connected inverter technology research:analysis and comparison of the various types of control and control mode, select optimal control strategy, and improve the algorithm based on it;(4)Introducing and analysis of the definition, cause and harm of Islanding, studying its passive detection method and active detection method, to finding the optimal detection method and simulating;(5)The design and implementation of the Grid-connected inverter: Analysis of main circuit topological structure, based on TMS320LF2407A, designing the grid-connected inverter control circuit from the driving circuit, protection circuit, data acquisition circuit and others, achieving the PLL control by software to make the grid-connected current real-time tracking of the electric voltage.