Conductivity of pressboard for HVDC insulation systems

Authors

  • Fabian Schober University of Applied Sciences Würzburg-Schweinfurt, Institute for Power Engineering and High Voltage Technology Ignaz-Schoen-Strasse 11, 97422 Schweinfurt, Germany
  • Stephan Harrer University of Applied Sciences Würzburg-Schweinfurt, Institute for Power Engineering and High Voltage Technology Ignaz-Schoen-Strasse 11, 97422 Schweinfurt, Germany
  • Andreas Küchler University of Applied Sciences Würzburg-Schweinfurt, Institute for Power Engineering and High Voltage Technology Ignaz-Schoen-Strasse 11, 97422 Schweinfurt, Germany
  • Frank Berger Technische Universität Ilmenau, Department of Electrical Apparatus and Switchgear Gustav-Kirchhoff-Strasse 1, 98693 Ilmenau, Germany
  • Marcus Liebschner Aalen University, Optics and Mechatronics Beethovenstrasse 1, 73430 Aalen, Germany
  • Christoph Krause Weidmann Electrical Technology AG, Technology Services and Innovation Neue Jonastrasse 60, 8640 Rapperswil, Switzerland
  • Wolfgang Exner Weidmann Electrical Technology AG, Technology Services and Innovation Neue Jonastrasse 60, 8640 Rapperswil, Switzerland

Keywords:

Scellulose, conductivity, HVDC transmission, insulation, pressboard

Abstract

The cellulosic material pressboard is a key component in insulation systems for HVDC (high-voltage direct current) equipment. Pressboard compounds are considered from a chemical point of view in order to link it in a subsequent study with electric conduction processes in pressboard. For a better understanding of pressboard, its manufacturing is described and fiber geometry is evaluated by SEM (scanning electron microscopy) analyses. Especially for HVDC insulation, pressboard conductivity is the most important property. For an air-impregnated pressboard sample, the dependence of conductivity on time, temperature and water content is presented. For this purpose, step response measurements in time domain are performed with a sensitive current device. Furthermore, the influence of oil-impregnation on pressboard conductivity is evaluated. The conductivity of oil-impregnated pressboard is up to 13 times higher than the conductivity of unimpregnated pressboard for the given conditions.

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Published

2013-11-01

Issue

Section

Original Scientific Papers