Tracking Three-Phase Untransposed Transmission Line Parameters Using Synchronized Measurements

The purpose of the study that is reported in this paper is to develop a method to estimate the parameters of untransposed overhead transmission lines using synchronized measurements. Considering the noise in the measured bus voltages and line currents, a three-phase static state estimation is employed first to estimate the states. Then, the parameters are tracked dynamically by a Kalman filter. State estimation and parameter tracking process are iteratively carried out to reduce the uncertainties that exist in the estimation function. In addition, a static parameter estimation method is proposed to estimate the initial values of line parameters. Several tests using simulated as well as actual recorded measurements are conducted considering a wide spectrum of line parameter variations. Results of these simulations are provided to illustrate how the proposed approach can successfully track line parameters under a variety of operating conditions.