Study On Islanding Detection Methods Of Three-Phase Grid-Connected Photovolatic Inverter

Now in the consumption of energy, the proportion of non-renewable energy is large, and because of the characteristics of non-renewable and energy increasingly tense situation,all that are driving the search for more environmentally clean renewable energy. Solar energy that is a kind of extremely rich reserves of clean energy has a very broad development prospect. One of the key issues is how solar power and conventional electricity achieve safety and effectively connecting. Islanding as the possible problems in the process of photovoltaic(PV)system connecting to power grid, bring hidden dangers to the safe operation of power grid. So,as a measure of islanding prevention, islanding detection technology is very necessary to study. In view of the island effect and detection technology, this paper, after reading a large number of relevant literature, has carried on the detailed research and discussion.First of all, the background of PV system, and its impact on the power grid, as well as the islanding are carried on the detailed analysis and summary. Secondly, the principle of islanding and islanding detection methods currently in use are carried on the detailed analysis. Thirdly, on the basis of a establishing the mathematical model of three-phase PV systems, designing the controller has carried on. Finally, a third harmonic injection islanding detection method has proposed, and the simulation and experiment are present.The method not only can detect islanding effectively, and also can play an role in improving power quality when normal power grid.