Wide Area Control of Governors and Power System Stabilizers With an Adaptive Tuning of Coordination Signals

This paper presents the formulation of Wide Area Control (WAC) signals for either coordinating all the governors of the system or coordinating simultaneously both the governor and the Power System Stabilizer (PSS) of each generator. This is achieved through the development of suitable WAC signals intended for the coordination of their common input signal (rotor speed deviation) having as objective the compensation of all the local and inter-area oscillations. Furthermore, an adaptive tuning method to estimate weights for each inter-generator interaction is also presented. This is required to regulate adaptively the level of the WAC contribution to all the local controllers. The weights are computed according to the electric connectivity between the generators. For the evaluation of the proposed methods, both offline and real-time simulations are performed on the IEEE 39-bus test system. The results indicate the substantial improvement of the system's stability when the proposed governor/PSS coordination is considered. The performance of the WAC scheme is further increased when the adaptive tuning procedure is applied. Finally, the requirement of having PMUs at each generator bus is relaxed by utilizing the coherency concept.