Wideband parameter estimation of three-phase untransposed frequency-dependent transmission lines from terminal measurements

This paper introduces a wideband parameter estimation approach for untransposed three-phase overhead transmission lines. The proposed method involves an accurate reconstruction of the 2-port nodal model of the line over a wide frequency band from terminal measurements obtained for a set of tests. The minimum norm least-squares method is applied for the solution of the overdetermined mathematical system resulting from these tests. The reconstructed model is further solved for the series impedance and shunt admittance matrices without the need for modal decupling techniques. Terminal voltage and current measurements used as inputs are simulated using software ATP for several tests that consider different tower configurations. The estimated parameters are compared with those computed analytically, with very close results when compared with analytical parameter calculation considering full frequency dependence.