高渗透率分布式光伏配电网暂态等值建模方法研究

Abstract With the increasing penetration of distributed photovoltaics (DPV) in distribution networks, the coupling and interaction between distribution networks and the upper-level grid have been continuously enhanced. To mitigate the risk of grid instability caused by the large-scale integration of DPV, it is imperative to establish transient equivalent models for distribution networks with high-penetration DPV. However, existing studies fail to meet the requirements of timeliness and interpretability for equivalent modeling of distribution networks in practical applications. In view of the above, this study proposes a transient equivalent modeling method for distribution networks with high-penetration DPV. Firstly, based on the intermediate equivalent model of distribution networks and industry standards, a clustering method is proposed using unit types and nodal voltages. Secondly, the initial clustering results are optimized based on nodal voltage magnitudes and total power outputs of sub-clusters. Thirdly, equivalent models for DPV are developed, and the equivalent impedance between each equivalent DPV units and the point of common coupling (PCC) of the distribution network is calculated. Subsequently, the equivalent load power is calculated based on the exchange power at PCC, as well as the output of the equivalent DPV model. Finally, simulations on the PSASP7 platform validate the proposed method.