Study On The Solar Photovoltaic System Charging Strategy

Energy depletion, environmental pollution, the use of traditional fossil fuels has begun to restrict the social and economic development. Harmonious nature, scientific development put forward to promote the rapid development of new energy systems. In the past two years, the installed capacity of photovoltaic system and photovoltaic industry have been a rapid increase, the state has made the PV industry to upgrade to a new level of development.Widely used VRLA batteries and photovoltaic cells are an important part of the photovoltaic power generation system which has been made as the main object of study in this paper. Through a combination of theoretical basis and experimental analysis, the paper is carried on in-depth discussion and study a reasonable for a reasonable and effective charge of the photovoltaic system strategy. Around in order to achieve maximum power charging a timely manner to improve the charging efficiency, focusing on mainly the following:First, the development of photovoltaic systems at home and abroad and the international expectations of the PV systems development as well as the development of charging technology are reviewed, and then put forward the main research direction of this thesis. Analysis is started from the basic knowledge of the characteristics of the photovoltaic cells and the internal battery reaction mechanism, affecting the capacity factor theory. Established a photovoltaic cell simulation model in MATLAB/Simulink environment which gives a theoretical basis for the thesis proposed charging strategy. The paper combines outdoor experimental work characteristics of photovoltaic cells, the design of a boost circuit based on the TL494complete photovoltaic boost charging process. On the basis of the outdoor experiments, a new MPPT method of new impedance matching method is proposed applies to photovoltaic systems in the battery charging, and obtained through the simulation study the rationality and feasibility of the method. The paper also gives the traditional design methodology of PV system, contact the actual design process, to extract a design method according to a power to maximize and cost savings. The SOC state of the battery is studied and a new method has been proposed to estimate the battery capacity by the terminal voltage in the battery cycle charge-discharge process.In order to improving the charging cost-effective of the greatest degree for small (micro) stand-alone PV system, some suggestions are given by experimental methods on the system voltage choice. Finally, according to the results of the study, a photovoltaic system experimental platform is established in Jinan, and then the related data is analyzed.