Research On Boost And Islanding Detection To Photovoltaic System

With the development of social production, and the increment of energy consuming and the deterioration of ecosystem environment, the energy crisis is becoming more and more prominent in the global scope. Solar energy is especially concerned by human because of its free pollution. Currently with price reduction of PV (photovoltaic) modules and development of PV technology, the role of PV system are gradually changed from supplemental energy to substitute energy. The PV system will be the trend among PV applications. This paper deal with such key problems as DC/DC converter, maximum power point tracking (MPPT) of PV array, islanding detection in detail. The paper also builds a simulate model of circuits of the DC/DC boost converter, and the islanding detection. The MPPT's control strategy is also presented. The more details about the work are as follows:1. The present situation and the development prospects of PV system at home and abroad areintroduced briefly. The function, classification and characteristic of grid-connected PV system are also introduced, by which the PV system can be got an overall understanding.2. A Boost-TL convertor is presented for DC/DC part. The principles and characteristics of Boost-TL converter are analyzed at length. And the formulas of the key parameters of the main circuit are derived and given out. The paper builds a simulation of Boost-TL converter, corresponding experiments are done.3. This paper analyzes the principle of the solar panel and the output characteristic for the solar cell under different temperature and isolation. A proper MPPT's control strategy is presented for Boost-TL converter. And then, the control software's flow charts are introduced.4. This paper analyzes the principle of islanding detection, compares several common islanding detection methods, builds a simulation of OVP/UVP, OFP/UFP and AFD, corresponding experiments are done.