Excitation control for large disturbances in power systems with dynamic loads

This paper presents a novel large-disturbance controller for power systems with significant induction motor (IM) load. Unlike the standard linearisation technique, a linearisation is used where the Cauchy remainder is included in the design process as a bounded uncertainty. Details of the process to obtain a bound on Cauchy remainder are given in the paper; the bound is used to design the robust minimax linear quadratic Gaussian (LQG) large-disturbance controller. An advantage of this approach over the existing linearisation scheme is the treatment of the nonlinear dynamic load model, in a rigorous framework, to design an excitation controller to enhance dynamic voltage stability. The efficacy of the proposed control strategy is evaluated through simulations on a benchmark four bus power system for various types of loads and large disturbances.