Impedance Parameters Estimation of Transmission Lines by an Extended Kalman Filter-Based Algorithm

The accurate knowledge of the electrical parameters of transmission lines is an important issue for, e.g., fault detection and location, stability analysis. In this sense, the reliability in which such parameters are determined shows to be crucial to the entire system operation. In this article, we propose the estimation of both phasors and parameters through a nonlinear approach by using the Kronecker product, in order to determine the Jacobian terms, and thereafter the extended Kalman filter (EKF). The parameters estimation is carried out recursively in the d-q domain, based on the phasor rotation dynamics for a given frequency. The results presented a reliable and accurate estimation compared to another approach based on Kalman Filtering method. The nonlinear approach, applying the Kronecker product and EKF, represents the original contribution of the proposed estimation method. Besides, this method is applicable to large systems, since the transmission line have to he modeled by the equivalent pi model using the hyperbolic corrections.