Optimal Planning of SOP in Active Distribution Networks Considering Load Balancing and Voltage Fluctuations

As a power electronic device, the soft open point (SOP) demonstrates significant potential in improving load balancing and mitigating voltage fluctuations in active distribution networks through its flexible power regulation capability. However, the rational determination of SOP allocation and capacity remains a critical challenge due to constraints in investment and operational costs. A multi-objective planning methodology for SOP deployment in active distribution networks is proposed to improve operational efficiency and system stability by economically taking load balancing enhancement and voltage fluctuation suppression. Firstly, the operational characteristics and mathematical model of SOP in active distribution networks are systematically analyzed. Three key indicators including the annual comprehensive cost, load balancing degree and voltage fluctuation index are introduced from the perspectives of balancing the economy and reliability of the active distribution network. Subsequently, the SOP siting and capacity planning model is established with three key performance indicators to ensure economic optimization while maintaining load uniformity and voltage stability. The optimization model is solved through second-order cone programming algorithm for enhanced computational efficiency. Finally, case studies are conducted on the modified IEEE 33-node test system to validate the proposed methodology.