A novel MIQCP method for FACTS allocation in complex real-world grids

• Quadratically constrained mixed integer programming applied to the FACTS allocation problem.
• Method determines type, quantity, compensation rating and number of devices simultaneously.
• Optimal TCSC and SVC allocation demonstrated on real-world Queensland HV transmission network.
• Results prove more reliable for real-world applications compared to linear based formulations.

This paper presents a novel Flexible AC Transmission Systems (FACTS) placement method based on mixed integer quadratically constrained programming (MIQCP). The method is capable of allocating both Static VAR Compensator (SVC) and Thyristor-Controlled Series Capacitor (TCSC) either separately or simultaneously, to determine concurrently their numbers, locations as well as sizes. The optimization objective is to maximize loadability and minimize compensation. The proposed MIQCP formulation partially incorporates key quadratic constraints, which were absent in mixed integer linear programming (MILP) placement methods reported in the past. The authors demonstrate significant improvements in accuracy over past MILP methods, with case studies presented on the simplified Southeast Australian network, and on a large scale real-world power system, Powerlink Queensland’s HV transmission network, with 886 buses and 1087 branches. In addition, results and observations for simultaneous allocation of multiple TCSCs and SVCs in these networks are demonstrated in this paper.