Electrical and Computer Engineering ETDs

Publication Date

Spring 2-10-2020


In high voltage systems, insulators may be used to separate conductors and these insulators are typically the limiting factor in the system’s operating voltage. When the voltage between two conductors is too large, the insulators can fail due to surface flashover. As systems become more compact, the threat of failure by insulator flashover increases, making the optimization of insulators a critical task for reliability.

Insulators at a vacuum interface are especially vulnerable to surface flashover. Insulators have been shown to holdoff more voltage in vacuum after being baked to remove imbedded surface gases. Ceramic materials are particularly attractive because, unlike polymers, they can be baked at very high temperatures without damage. To further increase the holdoff voltage, ceramic was configured as a high gradient insulator. A high gradient insulator is a stack of alternating layers of insulating and conducting material which has been shown to increase the holdoff voltage, under certain conditions. In this work, two approaches to high gradient insulators are explored.


High Gradient Insulators, Surface Flashover

Document Type




Degree Name

Electrical Engineering

Level of Degree


Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Jane Lehr

Second Committee Member

Mark Gilmore

Third Committee Member

Lisa Fisher

Fourth Committee Member

Andrew Fierro