Date of Award


Degree Name

Doctor of Philosophy


Electrical and Computer Engineering

First Advisor

Dr. Pablo Gomez, Ph.D.

Second Advisor

Dr. Richard T Meyer, Ph.D.

Third Advisor

Dr. Damon Miller, Ph.D.


Frequency-dependent, overhead transmission line, parameter estimation


The accurate and efficient determination of electrical parameters of transmission lines is essential when performing computer-aided analyses of power systems, including power-flow, state estimation, short-circuit, transient stability, power quality, and electromagnetic transients.

In this dissertation, a novel technique for wideband parameter estimation of frequency-dependent single-phase, three-phase transposed, and three-phase untransposed overhead lines, is proposed. The proposed technique utilizes terminal measurements of transient voltages and currents and is based on an analytical approach to solve the frequency domain 2-port nodal model of the line for the series impedance and shunt conductance per unit length as a function of the frequency. The EMTP/ATP software tool is used to produce emulated terminal measurements of voltage and current to be used as an input in the method. Since the method is defined in the frequency domain, the time domain terminal measurements are transformed to the frequency domain using the numerical Laplace transform (NLT). The estimated parameters are compared to those calculated analytically, demonstrating high accuracy for a wide frequency range. The proposed method is aimed at its application in transmission line protection and fault location based on terminal transient response. In addition, the minimum norm least-squares (MNLS) method is used in the parameter estimation of three-phase untransposed lines to solve an overdetermined system of equations resulting from the evaluation of the transmission line response for as set of tests producing distinct transient voltages and currents.

Access Setting

Dissertation-Open Access