Research On Autonomous Operation Of Microgrid With Photovaltaic Generators

Energy security,environmental protection,economic development,and other issues support an explosive growth of distributed photovoltaic(PV)power generation system in the modern power system.In order to deal with the problem of power supply reliability brought by high penetration of PV generators,islanded microgrids emerge.Islanded microgrids independent of power grid can not only achieve local consumption of distributed generators effectively,which reduces energy waste caused by light-abandoning,but supply reliable power for the important loads,which promotes social stability and economic development.However,for microgrids based on PV generation system,some technical problems are raised as follows:? The intermittence and volatility of PVs' output power make it difficult to operate and control microgrid;? The geographical dispersion of massive PV generation systems makes it difficult to manage so many PVs uniformly.As a result,how to balance the power flow inside microgrid in spite of the fluctuation of PV output,and how to design the autonomous operation scheme for multi-agent-based microgrid to improve the communication robustness,and achieve center-free control,are research hotspots and the focus of this paper.Based on distributed control theory,the autonomous control of microgrid based on PV generation system is concerned:i)Improve the individual control of PV system,enhance its friendliness to grid,and analyze the requirement to the dynamic of single PV when massive PVs are connected to power system;ii)Develop a novel distributed extremum seeking(DES)algorithm to estimate the production capacity of PV cluster,then on this basis study the real-time dispatch strategy of microgrid to place the dispatch function of control center into each PV system;iii)Design a new distributed average filtering algorithm to estimate the total demand of all loads and the power difference between all loads and PVs,and on this basis apply the finite time consensus control to the power control of microgrid to balance the power within microgrid and share power among PVs quickly and fairly;iv)Based on the results of i)-iii),establish the center-free control scheme to operate microgrid intelligently and distributively.