Control Strategy Research On Distributed Photovoltaic Power Generation Microgrid

In this work,a detailed analysis and research for the distributed photovoltaic microgrid control strategy is carried out,including the microgrid control strategy,the control algorithm of photovoltaic power generation system,and the establishment of simulation model with its validation analysis.Firstly,the background and significance of the research are introduced.The current research status of the photovoltaic power generation technology at home and abroad is analyzed in detail as well as the current status of microgrid control technology.Then the basic theory of photovoltaic power generation is described at length,and the basic principle and operating characteristics of photovoltaic cell are analyzed emphatically.The grid connected standard for photovoltaic grid connection and several methods and characteristics of MPPT maximum power point tracking implementation are introduced,which mainly include constant voltage control method,conductance increment method,and disturbance observation method,etc.Secondly,according to the characteristics of distributed photovoltaic power generation system,the using of microgrid structure is analyzed.The capacity size and the selection of the grid connected point are studied,and the overall efficiency of the grid connected photovoltaic system is analyzed based on the photovoltaic grid connected control strategy adopted in this paper.Besides,the islanding effect after system failure and how to detect it effectively are introduced.Moreover,through the establishment of simulation model,several key modules in the simulation link are described,such as boost link,DC/AC grid connected link,filtering link,and photovoltaic power grid connected system,etc.The impact of distributed photovoltaic grid connection on large power grid is also studied.Finally,the photovoltaic cells,single-phase photovoltaic grid connected system are simulated and analyzed along with the microgrid isolated mode with constant power control and micro grid P/Q control grid connected system.The effectiveness of the proposed grid connected control strategy is verified by the simulation and experimental.It is shows that the control mode and algorithm used in this paper meet the design requirements that can better realize the grid connected operation of distributed photovoltaic power generation,which also has important practical significance.