| With the world’s energy situation is becoming more and more tense, all countriesare vigorously developing clean energy. Photovoltaic energy has become an importantdirection of clean energy development for its characters of pollution-free and hugereserves, especially single phase grid-connected photovoltaic system has a very broadapplication prospects. Under this background, single phase grid-connected photovoltaicsystem as the research object. In this paper the research involves the maximum powerpoint tracking control technology, grid inverter system control strategy and islandingdetection technology, etc.Firstly, this paper analyzes the principle and characteristics of photovoltaic cells, thesimulation model of photovoltaic system is established in Matlab/Simulink environment,The Influence of the sun light and temperature on its output characteristic is simulated.Secondly, this paper introduces several common the maximum power point trackingcontrol methods. And set the module control simulation model of the disturbanceobservation method and conventional conductance increment method. Due to the poorperformance of the dynamic and steady state and the starting procedure, a variable stepincremental conductance algorithm is proposed. The simulation shows that the improvedalgorithm has good control performance.Thirdly, this paper analyzes the island effect of the PV system. Because of thecommon islanding detection method are flawed. So, a periodic disturbance of two-wayAFDPF islanding detection method is proposed. The experimental results show that theproposed algorithm has faster detection speed, and Reduce the influence of the loadproperties to the testing result.Finally, this paper analyzes the mathematical model of grid connected invertersystem and its mathematical model is established. In order to improve the grid inverteroutput current, this paper proposes a grid voltage feed-forward compensation controlstrategy, Through the simulation experiment results, the feasibility of the control schemeare analyzed. The result achieved good effect of interconnection. |
