http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Development of a methodology to discriminate incipient insulator faults from distribution system load
Insulator failure has long plagued transmission and distribution system power quality. The failure process begins when airborne contamination combines with moisture from atmospheric wetting to form a conductive pollution layer on the insulator surface through which leakage current can flow. The leakage current activity that occurs across the polluted insulator surface is referred to as an incipient insulator fault. Unless natural cleaning or corrective maintenance occurs, incipient insulator faults will eventually escalate into an overcurrent fault in the form of a flashover. It is these flashovers and the resulting service disruptions that degrade power quality. With the effects of deregulation looming, utilities are searching for ways to improve power quality by preventing these flashovers. To help improve power quality and maintenance system reliability, the Power System Automation Laboratory at Texas A&M University is investigating on-line condition assessment of distribution line insulators. The preliminary work focussed on the development of a methodology to discriminate incipient insulator faults from distribution system load. The development of this methodology is the focus of this thesis. The methodology included the following: 1. Investigating incipient insulator faults on contaminated insulators exposed to simulated atmospheric wetting 2. Investigating incipient insulator faults on contaminated insulators exposed to natural atmospheric wetting 3. Characterization of incipient insulator faults 4. Determining characteristics most likely to discriminate incipient insulator faults from distribution system load current From this work, the aggregate of the non-harmonic components and the high frequency energy of the leakage current were identified as having great potential for discriminating incipient insulator faults from distribution system load. Future work will determine the feasibility of these characteristics and possible the inclusion of additional characteristics for discriminating incipient insulator faults from distribution system load.
"Major subject: Electrical Engineering".
Issued also on microfiche from Lange Micrographics.
Includes bibliographical references (leaves 115-118).