Research On Planning And Operation Strategies Of Photovoltaic Power Stations Based On Complex Network Theory

The construction of large-scale photovoltaic(PV) power stations has brought new challenges for safe and efficient operation of power grids when relieve the strain on the electricity. Research on planning and operation strategy of PV power stations is of great significance to make full use of solar energy resources, to avoid the negative impact of PV power generation on the power system security and stability, and to improve power system reliability.The conventional methods for PV power station planning mainly consider the construction of a single station based on the evaluation of solar energy resources and the static topologies of power grids. In this study, a dynamical planning approach via complex networks is proposed by considering the dynamical generation and distribution of PV energy among multiple power stations. Both transmission distance and transmission energy are considered to measure the energy distribution efficiency. We analyze the effects of the statistical characteristics on the node equilibrium energy and the transmission distance. It is found that nodes with a high degree, betweenness, consumption or a low clustering coefficient are helpful in reducing losses in energy transmission and striking a balance between generation and consumption. Thus, planning schemes are put forward, including site selection schemes and capacity assignment schemes, which are based on degree, betweenness, consumption or clustering coefficient. The simulation results indicate that for site selection, the selection schemes based on consumption and clustering coefficient are more efficient, whereas for capacity assignment, the consumption-based scheme is the best in enhancing the energy distribution efficiency. This efficiency is more related to site selection under small-scale construction but more so to capacity assignment under large-scale construction. In order to improve the efficiency, the GN method for community structure is used firstly. Analysis shows that when the PV power station construction scale is less than 50%, by using this method can effectively improve the efficiency of electricity distribution.A cascading failure model is proposed for PV power distribution system based on ML model. Through the robustness analysis of each scheme under different proportion nodes random attacked, we found that the site selection has bigger influence on the system robustness. The location planning according to the clustering coefficient and the power consumption has higher robustness compared with the traditional planning scheme under random attacks, and zoning planning has higher robustness. The spread stage, overloaded and underloaded nodes, upper limit and lower limit of network resistance coefficient are further analyzed to understand the basic characteristics of the cascading failure in PV system and put forward preventive and emergency defense strategy.