Extended H∞ controller applied to frequency control of high-power generation system

In this study, the extended H_∞ control of Mita, Kuriyama and Liu (1993) is applied to the frequency control of a multi-area high-power generation plant. More specifically, the plant is focused as a two area electric power generation system, with two generators, two loads and a tie-line connecting them. This problem is interesting because of the existence of a zero at s=0 in the multivariable plant that causes a constraint in defining its steady state. The paper discusses how to establish a suitable generalized plant´s structure for such a problem in order to design a H_∞ optimized control system that is able to reject load step disturbances asymptotically, i.e., a controller having poles at s=0. As an example, 3 extended H_∞ controllers are designed and simulation results are shown. Some discussion is made about how to tune the controller from parameters of weighting functions of the generalized plant