Optimizing static interphase power controllers (SIPC) placement: A comprehensive multi-objective strategy for enhanced performance of the electric transmission networks

The increasing operational stress on modern transmission networks, driven by large-scale integration of renewable energy sources, necessitates advanced and flexible power flow control solutions. Among series FACTS devices, the Static Interphase Power Controller (SIPC) offers a highly flexible architecture with enhanced controllability; however, its optimal placement from a system planning perspective has not been investigated so far. This paper presents, for the first time, a comprehensive multi-objective framework for the optimal placement and parameter tuning of SIPC in power systems. A coordinated planning–operation strategy is proposed in which SIPC investment cost, generation operating cost, power flow controllability, and transmission line loading are simultaneously optimized. The resulting nonlinear, mixed-variable problem is effectively solved using a Multi-Objective Particle Swarm Optimization approach, enabling the extraction of Pareto-optimal solutions that reveal explicit trade-offs between economic and technical objectives. Unlike conventional approaches, the proposed framework optimizes SIPC location and control variables concurrently, providing enhanced decision support for system operators. The effectiveness of the proposed method is demonstrated on the IEEE 24-bus transmission system. Numerical results show that installing a single SIPC at the optimal location can significantly reduce system operating costs while maintaining acceptable voltage profiles and line loadings within prescribed limits. The Pareto-based analysis further indicates that higher investment costs do not necessarily lead to superior operational benefits, highlighting the importance of multi-objective decision-making. Overall, the proposed approach expands the practical applicability of SIPC and provides a systematic planning tool for improving the economic and operational performance of transmission networks. • A combination of planning and operating objective functions is used. • Placement of SIPC as a very flexible FACTS device for the first time. • The process of finding the appropriate control values for a device is carried out simultaneously with the optimal placement procedure. • The best place to install the SPIC provides opportunities to reduce operation expenditures while improving the system's performance.