On Decentralized Control of a Multimachine Power System: A Comparative study

In this paper, our focus is to compare two decentralized con- trol laws implemented to a three-machine power system which generators are strongly nonlinear interconnected. We present first a linear decentral- ized control, which gains depend on the system nonlinearity, and confirm, via simulations, its ability to enhance the system transient stability. The second technique is a nonlinear decentralized optimal control based on a successive approximation approach where the nonlinear decentralized con- trollers are determined by the transformation of each high order coupling nonlinear two-point boundary value (TPBV) problem into a sequence of linear decoupling TPBV problems. We develop algorithmically and im- plement this decentralized optimal control to the three-machine power system. We prove, via advanced simulations, that this approach brings better performances than the linear decentralized controller, improving effectively transient stability of these power systems in a few steps.