The Control Technology Of Photovoltaic Power Generation In Microgird

Access to a large number of distributed power generation system will bring a serious impact for the operation of large power grid. Access to the power system with structural form of microgrid not only can solve problem of access to large-scale distributed generation. but can give full play to the advantages of distributed power generation. And photovoltaic power generation has been recognized as a best of renewable energy in a number of distributed energy. so the research of control technology of PV power generation in microgrid is great significance.Traditional control strategy for photovoltaic power generation has ceased to apply to a microgrid of flexible operation requirements. Therefore, the control strategy of PV power generation in microgrid is studied mainly in the paper. According to the operational characteristics of microgrid. a new type of grid-converter control strategy with the droop characteristics is adopted. In the grid-connected mode of microgrid. photovoltaic power generation takes MPPT control to achieve the maximum power output, and the inverter with PQ control strategy based on droop characteristics makes the active, reactive independently control. In the islanding mode of microgrid. photovoltaic power generation takes power control to limit output power that is according to load requirement, the inverter with V/f control strategy based on droop characteristics can achieve a reasonable distribution of load power. The control strategy can be achieved stable operation of microgrid in different modes.The simulation model of microgrid is established through PSIM software. The operating characteristics of photovoltaic power generation are analyzed, from the transition process of grid-connected to islanding mode, from the transition process of islanding mode to grid-connected. in the islanding mode. and under the conditions of various light intensity and temperature effects for PV cells. The simulation results show the correctness and validity of control strategy. A photovoltaic power generation experiment platform is established with DSP. The maximum power point tracking control and limited power control of PV is achieved by the disturbance observation and disturbance observation method of limited power. At the same time. the control strategy of the inverter is studied experimentally.