Simulation Research On Controlin Gird-Connected PV System

Human beings are actively searching for a new energy to solve the problem of sustainable development because of the growing shortage of traditional energy and accelerating pollution problems of fossil fuels. To be a future substitute for conventional energy sources, solar source is especially attached by the human as a kind of abroad and no pollution source. Photovoltaic generate electricity gird-connected technology has become the main form of the solar application. Firstly, this paper introduces PV gird-connected system in detail and researches on its control methods deeply. In the last, this paper has a preliminary study on the capacity of the distribution network adopting the photovoltaic generating.The photovoltaic technology is developing very quickly, but the high cost of system and low power generation efficiency are still restricting its popularity application.In order to improve the photovoltaic efficiency, this paper proposes one new method based on the hysteresis disturbance tracking method and the constant current method from the analysis of the existing maximum power point tracking control methods and comparison of grid-connected inverter control technology. This new method accounts to solve the problem of tracking speed and to eliminate power disturbances, it achieves the requirements of fast-track and high-precision in optimizationprocess in theory. On gird-connected inverter control, this paper designs a method based on repeat of the PI current control and adding the voltage feed-forward link to further reduce the power grid voltage disturbances. The corresponding simulation model is setted up in MATLAB/Simulink; related simulation is done at the same condition of parameters. The results show that the improved MPPT hasa rapid and high-precision tracking consequent in the case of mutations of externalenvironments, and gird-connected current total harmonic distortion can basically meet the IEEE grid standard. The simulation results are consistent with the theoretical analysis.