Dc Voltage Insulating Properties of Various Inorganic Materials in Hydrogen Atmosphere at High Temperatures

Koichi Takahashi, Nobuko Hanada, Masayoshi Ishida

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In this study, the dc voltage insulating properties in a hydrogen atmosphere at high temperatures (600 °C to 850 °C) were evaluated for alumina (Al2O3), magnesia (MgO), silicon nitride (Si3N4), and mica (KMg3(Si3Al)O10(OH)2) to comprehend the difference in the insulating properties of oxide, nitride, and minerals. The activation energies of the electrical conductivity of alumina and magnesia in hydrogen were larger than those in air. On the other hand, the electrical conduction values for silicon nitride and mica in hydrogen were the same as those in air. Therefore a low oxygen partial pressure would have some influence on the electrical conduction of oxides. Increasing the temperature did not result in a large change in the electrical conduction mechanism in any of the materials in either atmosphere. The maximum partial discharge (PD) in hydrogen tended to increase compared to that in air at high voltage. The applied voltage at which the maximum amount of PD started to increase rapidly became lower with increasing temperature in all materials and in both atmospheres. The total amount of PD tended to decrease with increasing temperature in all materials and in both atmospheres. However, above a certain temperature, the total amount of PD either increased or showed a slight decrease.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalElectrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)
Issue number4
Publication statusPublished - 2015 Dec 1
Externally publishedYes



  • dc voltage insulating property
  • high temperature
  • hydrogen
  • inorganic material
  • partial discharge
  • solid oxide fuel cell

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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