Aggregation of Distributed Resources in Distribution System Based on Distribution System Security Region

Distributed resources in the distribution system ex-hibit strong flexibility. The Distribution System Operator (DSO) further participates in the scheduling of the transmission network by aggregating these flexible resources at the distribution system's point of common coupling (PCC). However, existing research methods cannot balance the complexity of solving aggregation models with computational accuracy, leading to a lack of effective coordination between flexible resources and the transmission network. Therefore, this paper proposes a method for characterizing the scheduling boundary of the distribution system based on the security region of the distribution system, aimed at better aggregating distributed flexible resources. First, an analytical model of the convex security region of the distribution system is proposed based on the radial power flow of the distribution system. Furthermore, the proposed security region model replaces the power flow constraints in the original resource aggregation model of the distribution system, and finally, the total aggregated power output of the distribution system at the PCC is calculated using the vertex enumeration method. Through case analysis, the superiority of the proposed model and computational method in terms of computational complexity and accuracy is verified.