A Modeling Approach for Electric Power Transmission Lines in the Presence of Non-Fundamental Frequencies

A Modeling Approach for Electric Power Transmission Lines in the Presence of Non-Fundamental Frequencies Valentina Cecchi Karen Miu, Ph.D. In light of the fact that modern power systems are expected to exhibit an increased level of harmonic and inter-harmonic frequency components, a modeling tool for electric power transmission lines was developed to determine the appropriate model structure under non-fundamental frequencies. The tool, designed for system studies, consists of a step-by-step procedure that determines the model segmentation and the corresponding parameter values of each segment. It is based on a user-defined level of accuracy and given frequencies of interest. In order to assess the accuracy of a line model, its performance is characterized through wave propagation, specifically voltage attenuation and phase shift, and is compared to the distributed parameter line model. The line modeling approach utilizes a state-of-the-art simulation tool to obtain the receiving-end voltage of the line models at the frequencies of interest. The softwarebased approach is validated with hardware tests performed within the Drexel University power engineering laboratories. An experimental platform, comprising an instrumentation and measurement system and power hardware, was designed and developed specifically to study waveform propagation in lumped circuit equivalents of transmission lines at non-fundamental frequencies. For demonstration purposes, the proposed modeling approach was applied to a short-length and a long-length line of given cable type. Results were then validated through hardware tests.