Controller design with model identification approach in wide area power system

Using wide area monitoring systems (WAMS) offers a possibility for an integrated measurement-based and model-based control, which suits to the operation of large electric power system (EPS), along with online analysis. This paper presents studies on a model identification approach with the use of synchronous measurement data to represent an equivalent system. Firstly, in the study, the coherent generators in each area of large EPS are determined by the mutual information theory. Then, state-space two-input two-output models are identified for a single generator representing the coherent area. The model identification algorithms; least-square (LS), instrumental variable (IV) and subspace state-space (N4SID) based generalized Poisson moment function (GPMF) are used. Finally, the controller is designed with the identified model at WAMS level by reducing the H^∞ norm of its closed loop transfer function as much as possible. The centralized controller at WAMS level is demonstrated to stabilize the speed deviations of each generator between any two areas in the large EPS. The study is investigated with different input signal variable excited by different pattern of under disturbances.