The Study Of Grid-connected Photovoltaic Generation System Based On MATLAB Simulation

With the increasingly serious energy crisis and environmental pollution problems,the development and utilization of new energy is particularly important. Solar energywith its unique advantages to the international community recognized as the idealalternative energy, making the grid-connected PV system has become a hot researchtopic in the new energy development. Single-phase photovoltaic power generationsystem as the object of study. In this paper the research involves the characteristics ofphotovoltaic cells, the maximum power point tracking control technology, and the gridinverter system control strategy, islanding detection technology, etc.First, the simulation model in MATLAB/Simulink is set up according to thephotovoltaic cells with mathematical model of engineering in this paper. By using theparameters of a battery, which from some company, the simulation model has beenestablished. The simulation shows that the battery characteristic curve is correspondwith the parameters of the manufacturers.Second, this thesis summarizes several common the maximum power pointtracking control methods, and set up each child module model of the system. Thesimulation shows that the system which changes in external factors can quickly trackthe maximum power point. Due to the respective shortcomings of the traditionalalgorithms in practical application, clonal selection algorithm in the artificial immunesystem is applied to the PV MPPT, achieving a good dynamic response. Because of theimmune system’s effective mechanisms and features makes the clonal selectionalgorithm can track maximum power point in real-time.Then, the grid-connected photovoltaic inverter control strategy is studied. Thesimulation model is established based on combining several control strategies, thenanalyzing and comparing the results: composite control based on phase-locked looptechnology and grid voltage feed-forward compensation strategy, with satisfactorycontrol, and the harmonic content THD minimum; In addition, based on the island effectin grid-photovoltaic system, the common method of active frequency drift has beenrealized by the simulation analysis, and proposes the AFDPF detection algorithm basedon periodic disturbance. The simulation shows that the algorithm has a fast detectionspeed, and the properties of load on discrimination results are considered. Finally, for the convenience of calling each simulation model, in GUI interfacerealizes interactive, which can realize the parameter establishment, the simulationwaveform display, simple wave treatment etc.