Decentralized adaptive PI control strategies for frequency control of interconnected systems

Algorithms for load frequency control of interconnected power systems in the presence of known constant plus time-varying disturbances are investigated. First, we have developed a decentralized PI controller based on decentralized state estimation. Controller based estimator is designed by exploiting the combine advantage of linear quadratic problem and eigenvalue assignment problem. PI controller does not work satisfactorily in the presence of time-varying disturbances. Then, we proposed an effective decentralized control scheme which is a combination of PI controller plus an adaptive controller. It is implemented on a hybrid computer. Hybrid computer control techniques combine the decision, storage and branching capabilities of the digital machine with the high speed solution of dynamic system equation on the analog machine. Simulation results present the advantages of the procedure on the two-area power system control design.