Research on Transient Equivalent Modeling Method for Large-Scale Distributed Photovoltaic in Distribution Networks

The continuous increase in the penetration rate of large-scale distributed photovoltaics in the distribution network has put forward higher requirements for the safe and stable operation of the power grid. Transient simulation is an important means of studying the safe and stable operation technology of power grids, but the existing transient simulation techniques are difficult to meet the simulation timeliness and accuracy requirements of high penetration distributed photovoltaic power grids. In view of this, this article proposed a large-scale distributed photovoltaic transient equivalent modeling method for distribution networks considering dynamic characteristics and electrical distance. Firstly, based on the analysis of the distributed photovoltaic transient response theory and industry standards, a clustering method based on unit type and electrical distance was proposed to divide the large-scale distributed photovoltaic into several sub clusters; Secondly, according to the principles of “consistent model” and “power conservation”, the distributed photovoltaic of the same sub cluster were aggregated into an equivalent unit; Furthermore, by using the equivalent lossless network construction method and node elimination method, an equivalent network was constructed between the equivalent power/load access points and the point of common coupling between the distribution network and the higher-level power grid, forming the final equivalent model; Finally, a simulation model was built based on the PSASP7 platform to verify the effectiveness of the proposed method in this paper.