Coordinated dynamic voltage stabilization based on model predictive control

Keeping voltages of all buses within acceptable bounds is very important for power system operations. This paper presents an approach for optimal coordination of static var compensators (SVCs), transformer under load tap changers (ULTCs) and load shedding to improve voltage performance following large disturbances. The approach is based on model predictive control (MPC) with a decreasing control horizon. The MPC formulation leads to a mixed integer quadratic programming (MIQP) problem, since both continuous and discrete controls are considered. Trajectory sensitivities are used to evaluate the effect of controllers on voltage performance. The iterative optimization process of MPC helps ensure that errors introduced due to any model inaccuracies and approximations are minimized. The MPC based coordination of these controllers is applied to a modified WECC system to enhance the voltage performance and to a modified 39-bus New England system to prevent voltage collapse.