Optimal siting and sizing of soft open points in active electrical distribution networks

Soft open points (SOPs) are power electronic devices installed to replace normally open points in active electrical distribution systems. SOPs can provide active/reactive power flow control and voltage regulation under normal operating conditions as well as fast fault isolation and supply restoration under abnormal conditions. The application of SOPs can improve the controllability of distribution systems, thus further enhances the economy, flexibility and reliability of the grid. In this paper, considering the long-term operation characteristics of distributed generation, a mixed integer non-linear optimization problem is formulated to optimally determine the siting and sizing of SOPs based on the typical operation scenarios generated by Wasserstein distance. It is then transformed to and solved as a mixed integer second-order programming model. Finally, case studies on the IEEE 33-node system and Taiwan Power Company distribution system are used to verify the effectiveness and efficiency of the proposed method.