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Title: Breakdown and Partial Discharge Measurements of Some Commonly Used Dielectric Materials in Liquid Nitrogen for HTS Applications

Abstract

For high temperature superconducting (HTS) power applications it is necessary to improve the understanding of the dielectric properties of materials in a cryogenic environment. It is necessary to know the breakdown strength of materials and systems as a function of gap in order to scale to higher voltages. The partial discharge (PD) onset voltage for materials is also very important since the primary aging mechanism at cryogenic temperature is PD. Another important design characteristic is the surface flashover voltage of a material in liquid nitrogen as a function of gap. With these characteristics in mind, several generic materials were investigated under a variety of electrode and gap configurations. The impulse breakdown voltage and PD onset of three types of commercial polyetherimide, filled and unfilled, were measured at room temperature and 77 K. A modest increase in PD onset voltage was observed at the lower temperature. Breakdown voltages of fiberglass reinforced plastic (FRP) cylinders for two wall thicknesses were measured which showed a decrease in strength at the larger gap. Breakdown voltages for liquid nitrogen using a sphere-plane electrode geometry were measured. Also flashover voltages along a FRP plate immersed in liquid nitrogen were performed for sphere-plane and rod-plane electrodes atmore » 1 bar pressure. It was found that the breakdown voltage increased only slightly with increasing gap lengths.« less

Authors:
 [1];  [1];  [1];  [1];  [2];  [3]
  1. ORNL
  2. Consultant, SuperPower, Inc.
  3. SuperPower Incorporated, Schenectady, New York
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
OE USDOE - Office of Electric Transmission and Distribution
OSTI Identifier:
931669
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: Applied Superconductivity 2006, Seattle, WA, USA, 20060827, 20060901
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AGING; BREAKDOWN; CRYOGENICS; DESIGN; DIELECTRIC MATERIALS; DIELECTRIC PROPERTIES; ELECTRODES; FIBERGLASS; FLASHOVER; GEOMETRY; NITROGEN; PLATES; REINFORCED PLASTICS; SUPERCONDUCTIVITY; Cryogenic dielectrics; dielectric breakdown; partial discharge; surface discharges

Citation Formats

James, David Randy, Sauers, Isidor, Ellis, Alvin R, Tuncer, Enis, Tekletsadik, Kasegn, and Hazelton, Drew. Breakdown and Partial Discharge Measurements of Some Commonly Used Dielectric Materials in Liquid Nitrogen for HTS Applications. United States: N. p., 2007. Web.
James, David Randy, Sauers, Isidor, Ellis, Alvin R, Tuncer, Enis, Tekletsadik, Kasegn, & Hazelton, Drew. Breakdown and Partial Discharge Measurements of Some Commonly Used Dielectric Materials in Liquid Nitrogen for HTS Applications. United States.
James, David Randy, Sauers, Isidor, Ellis, Alvin R, Tuncer, Enis, Tekletsadik, Kasegn, and Hazelton, Drew. Mon . "Breakdown and Partial Discharge Measurements of Some Commonly Used Dielectric Materials in Liquid Nitrogen for HTS Applications". United States. doi:.
@article{osti_931669,
title = {Breakdown and Partial Discharge Measurements of Some Commonly Used Dielectric Materials in Liquid Nitrogen for HTS Applications},
author = {James, David Randy and Sauers, Isidor and Ellis, Alvin R and Tuncer, Enis and Tekletsadik, Kasegn and Hazelton, Drew},
abstractNote = {For high temperature superconducting (HTS) power applications it is necessary to improve the understanding of the dielectric properties of materials in a cryogenic environment. It is necessary to know the breakdown strength of materials and systems as a function of gap in order to scale to higher voltages. The partial discharge (PD) onset voltage for materials is also very important since the primary aging mechanism at cryogenic temperature is PD. Another important design characteristic is the surface flashover voltage of a material in liquid nitrogen as a function of gap. With these characteristics in mind, several generic materials were investigated under a variety of electrode and gap configurations. The impulse breakdown voltage and PD onset of three types of commercial polyetherimide, filled and unfilled, were measured at room temperature and 77 K. A modest increase in PD onset voltage was observed at the lower temperature. Breakdown voltages of fiberglass reinforced plastic (FRP) cylinders for two wall thicknesses were measured which showed a decrease in strength at the larger gap. Breakdown voltages for liquid nitrogen using a sphere-plane electrode geometry were measured. Also flashover voltages along a FRP plate immersed in liquid nitrogen were performed for sphere-plane and rod-plane electrodes at 1 bar pressure. It was found that the breakdown voltage increased only slightly with increasing gap lengths.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

Conference:
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  • Abstract: Liquid nitrogen (LN2) is used as a coolant and electrical insulation in many High Temperature Superconducting (HTS) applications. Hence a good understanding of the breakdown characteristics of this medium under a variety of practical electrode geometries and conditions is needed for design of high voltage equipment. While there is considerable literature on breakdown of LN2 gaps for uniform (plane-plane) or quasi-uniform electric fields (sphere-plane), there is much less data available for highly non-uniform field gaps and for surface flashover along insulators. In this paper we present results on sphere-plane and cylindrical rod-plane gaps in LN2 as a function ofmore » sphere and rod diameters and radius of the rod edge at 1 bar pressure. In addition the surface flashover voltages of Fiber-Reinforced Plastic (FRP) in LN2 with these electrode arrangements will also be reported.« less
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