ESIC Seminar Olsen Oct 1

Recent Advances in Applying Electromagnetics to Transmission Line Design
In this seminar, recent advances in applying electromagnetics to the design of high voltage transmission lines will be discussed. First, some background will be provided about how the spatial distribution of electric field can be used to understand how transmission line design parameters ae related. For example, it can be shown that increasing power flow on long transmission lines necessarily results in reduced critical flashover voltages. Second, it has been known for many years that corona loss attenuates switching surges as they propagate along high voltage transmission lines. However, the effect is difficult to analyze due to its non-linear characteristic and has not been included in the commonly used tools for calculating surge voltages. A method to study corona surge voltage attenuation which accurately accounts for corona attenuation and represents a better design tool for high capacity, high voltage transmission lines will be described.
Finally, an alternative theory for calculating critical flashover voltage which identifies breakdown based on the ability of the pre-breakdown leader-streamer system to survive the region of minimum electric field between phase conductors will be described. Results obtained with the method compare well to four independent sets of experimental data for phase-to-phase flashover from the literature. This model will enable accurate calculation of critical flashover voltages and when coupled with the work on corona attenuation of switching surges will lead to transmission line designs that can be better optimized for increased power flow.