Research On The Maximum Power Point Of The PV Array Under The Partial Shade

In recent years, as a new type of the green energy, more and more people become to pay attention to solar energy, because of its adequacy, security, universality, cleaning of pollution.The solar photovoltaic system also can be called the solar photovoltaic for short, it can turn the sunlight into the electricity directly, but now the cost of photovoltaic panels is very high, and the efficiency is not very ideal, so in order to make good use of solar energy, it’s necessary that research on the maximum power point of a PV system.The maximum power point of the solar photovoltaic system is the maximum power output of the PV array. This paper mainly research the dynamic trajectory of the maximum power point of a PV array when the temperature and light intensity changes, so we can find out the maximum power point more convenient, as far as possible to guarantee the P V array to maintain the maximum power output.This paper analyses the PV module with bypass diode operation state, based on the establishedmodel constraints implicit complementarity of photovoltaic array, the principle is analyzed, and it shows hecorresponding algorithm which was based on merit function algorithm and draws up a detailed analysis of the dynamic changes of the maximum power point under the partial shade.The main contents are as follows:Firstly, it introduces the research background and significance, and the main work of this paper;Secondly, it introduces the definition and classification of the solar photovoltaic system and the structure of PV modules.It gives the implicit complementarity model of photovoltaic array.It Analyses the photovoltaic cell’s operation principle and the output characteristic curve, verifies the output characteristics in different temperatures and sunlight intensity.It introduces the principle of the common DC-DC converter, the inverter and the energy storage devices;Then, it gives thecorresponding algorithm which was based on merit function algorithm.And it proves to besuitable for large PV station modeling, analysis and simulation under all kinds of shadow conditions;The next, it introduces the principle of maximum power point tracking, and give a detailed description of the disturbance observer method, the constant voltage method, the conductance increment method, the Kalman estimation, and analyses the principle, flow charts and the superior and the disadvantage of them.It analyses Longyuan Goermu PV power plant, verifies the dynamic trajectory of the PV array maximum power point of one day, the seasons change and the shadows moving. Finally, it gives a summary of this paper and prospects for the future direction.