Enhanced particle swarm optimisation applied for transient angle and voltage constrained discrete optimal power flow with flexible AC transmission system

Transient stability constrained optimal power flow (TSCOPF) is increasingly important as many modern power systems nowadays have been forced to operate close to their stability limits. In this study, a non-convex mixed integer non-linear program (MINLP) TSCOPF model with consideration of valve-point effects and discrete control variables is first presented, in which the energy-based transient angle and voltage constraints are simultaneously considered as an integrated stability control process. The proposed model is general and flexible with support for any complex dynamic components, including detailed generator model and flexible AC transmission system (FACTS) devices, valve-point effects and discrete control variables. An enhanced particle swarm optimisation with dynamic adjusted inertia weight and shrinking Gaussian distribution disturbance is then proposed to solve this challenging MINLP-TSCOPF problem with comprehensive testing and evaluation using a benchmarking MINLP mathematical function and two representative power systems with FACTS devices.