Research On Control Strategy Of Distributed Photovoltaic Grid-connected Inverter System

Photovoltaic Grid-connected Systems can effectively using the solar energy, then it could be effectively feedback to the power systems. At the end of the2007, the installed capacity of all the Photovoltaic Grid-connected Systems reached the100MW in China, and the whole industrial chain from raw material to photovoltaic grid-connected system were built preliminary, it provided the perfectly future development on the Photovoltaic Grid-connected Systems.In this paper, it studied the platform of simulation and analyzed the types of Photovoltaic Grid-connected Systems, it studied the model of all the types of Photovoltaic Grid-connected Systems include the unadjusted Photovoltaic Grid-connected Systems and adjusted Photovoltaic Grid-connected Systems, centralized and distributed photovoltaic grid-connected system. It studied the method and algorithm about the MPPT in the Photovoltaic Grid-connected Inverter System and constitutes of the quasi-single-stage, then it analyzed and applied detect and reactive power compensation with the MPPT and the simulation about the method of reactive power and harmonic detect algorithm in the paper. At the end of the paper, it introduce the islanding detecting methods in the Photovoltaic Grid-connected Inverter Systems such as condition about islanding detecting methods in the IEEE Std. In the process design of photovoltaic (pv) grid inverter, power grid dynamic process, based on the characteristics of the grid, how to stabilize the dc bus voltage technology is studied, put forward the corresponding control strategy and Simulink dynamic simulation, the research and design of photovoltaic (pv) grid inverter system experiment, has a certain guiding role in theory. It will introduce the studied content one by one in the paper. Finally, the paper puts forward three phase photovoltaic grid-connected power generation system, has the advantages of simple structure, low cost. Can be convenient to study and formulate the control strategy for validation. Simulation confirms that the practicability and reliability of distributed photovoltaic (pv) grid inverter system, fully shows the system design method applied in the power electronics bright prospects.