Reduction of IBR-dominated Distribution Networks by Multi-port Synthesis and Clustering

A challenge posed by the increasing penetration of inverter-based resources (IBRs) in distribution networks is how to efficiently simulate a transmission system with a large number of them, since this leads to an "explosion"in system complexity. This paper presents a two-step reduction method for IBR-dominated distribution networks. In the first step, the approach synthesizes a distribution network as a multi-port: one port at the substation connecting it to the transmission system and the others for each IBR connected to the feeder. Then, in the second step, IBRs at the connecting ports are possibly clustered, thus reducing their number. The method differs from others in the literature since it is numerical and can handle clusters of IBRs with different power ratings and set-points. Simulation results of a distribution network with IBRs show the effectiveness of the method.