Estimation of power quality using an unscented Kalman filter

The present study proposes a novel method of tracking the time varying frequency and amplitude of a distorted power frequency signal using an unscented Kalman filter (UKF). The UKF is a derivative free estimator which does not compute Jacobian matrices and therefore offers significant computational advantages over the extended Kalman filter (EKF). A new model structure is proposed for estimation of amplitude and frequency. The performance of UKF has been compared with those of EKF considering signals which can represent worst case measurement and network conditions in a typical power system. Results of simulation demonstrate that under identical conditions, the performance of both UKF and EKF are similar with less computations with UKF.