A Linearization Based Model Equivalent Method for Distributed Photovoltaic Generation Clusters

Recently, increasing distributed photovoltaic (PV) generations are penetrated in power system demand side, forming PV clusters. To model the dynamics of PV clusters, the model equivalence method can be used to reduce the computation complexity and simulation time, which can benefit power system security and stability analysis. In this paper, a simple and novel PV model equivalent method based on the model linearization is proposed. Firstly, a simplified PV model structure together with its parameter identification method in this paper is introduced. Then, the process of PV model linearization and parameters simplification is discussed, after which the PV model equivalent method is proposed accordingly. Afterward, the effectiveness of the proposed method is validated in different situations based on the disturbance events generated in the WSCC 9 bus system. Meanwhile, the relationship between equivalence effectiveness and PV parameters is analyzed. The results show that the proposed PV equivalent model in this paper can follow the dynamics of aggregated PV clusters well.