Research On Reactive Power Compensation In Large-scale Photovoltaic Access Area

As a renewable clean energy, Solar photovoltaic power generation got wide attention,because of the environmental impact of photovoltaic power generation, and in recent years, the scale of PV power stations is also growing, so, after the photovoltaic access to the system, the impact of reactive compensation optimization has become a new focus of research.This paper takes the large-scale photovoltaic grid-connected system as the research object,it is mainly divided into the influence of large-scale photovoltaic access on system and the choice of reactive compensation location, and the determination of capacity in three aspects.This paper firstly establishes the mathematical model of PPC's (Point of Common Coupling) voltage deviation, theoretically analyzes the change of photovoltaic power station's access site voltage with the change of photovoltaic power station output, and takes Qinghai power grid as an instance for a simulation study of reactive power compensation capacity and photovoltaic power output change's influence on voltage and the correlation between photovoltaic output change and reactive compensation equipment tide. Then, the reactive power voltage sensitivity index is used to calculate the effect on the nodal voltage of each compensating point in PV grid-connected system, and the preferred position of the reactive power compensator is judged by the size of the sensitivity value. Finally, taking Qinghai power grid as an example, the mathematical model of reactive power compensation in photovoltaic system is established, the particle swarm optimization algorithm is improved, and the optimizing ability and convergence speed of PSO (Particle Swarm Optimization) are improved,and the compensation capacity is determined, apply improved POS algorithm.In this paper, the model of Qinghai Power Network is calculated and network environment for a large number of photovoltaic power station access to the grid, the third chapter through the PSASP (Power System Analysis Software Package) simulation software analysis, the fourth chapter through the MATLAB programming get conclusions that the size of compensation capacity in13 nodes and 6 photovoltaic power station annular network.