This paper presents a method for increasing the reliability and improving the estimation of the angular frequency of a local load bus that is essential for the operation of the wide area power system stabilizer (WAPSS). In this method, the local bus frequency is estimated from two completely different methods, then the results of estimation are combined using a weighting method based on an unscented Kalman filter (UKF) and the Kalman measurement covariance. To evaluate the performance of the proposed method the transient stability of a two-area power system in presence of a wide area power system stabilizer has been studied by simulating the power grid as a nonlinear dynamic system via PST toolbox. The fusion estimation method is also investigated on the New England power system test case.
