Simultaneous siting and sizing of Soft Open Points and the allocation of tie switches in active distribution network considering network reconfiguration

Soft Open Points (SOPs) are power electronic devices and emerging flexible interconnections. The active and reactive power flow flexible controllability of SOP facilitates to improve the performance characteristics of the networks. To evaluate the contribution of SOPs to operational characteristics improvement, instead of a fixed number and an optimized configuration of SOPs is necessary. In addition to optimal siting and sizing of SOPs in distribution networks, considering the smart switching capability of SOPs compared to conventional switching through tie switches is important. This issue affects the decision of simultaneous investment for these types of equipment. Existing studies have not considered the coordinated presence of SOPs and candidate tie switches in a planning scheme for allocating them simultaneously. Here, a stochastic scenario-based planning model is proposed to determine the optimal sites and sizes of SOPs and the allocation of tie switches simultaneously while obtaining the optimal operation strategy of these devices during the network reconfiguration process. The model is formulated using the second-order cone programming approach. The optimization problem is solved considering renewable power production scenarios and different loading conditions. Finally, the proposed model is conducted on the IEEE 33-bus and 69-bus systems, and the results are presented.