The Improvement and Diagnosis of DC Degradation Properties with The Equivalent-Circuit Analysis of ZnO Varistors

ZnO 바리스터의 등가회로 분석을 통한 DC 열화특성의 향상과 진단

  • 소순진 (원광대학교 전자재료공학과) ;
  • 김덕규 (원광대학교 전자재료공학과) ;
  • 김영진 (전주공업고등학교 전기과) ;
  • 소병문 (익산대학 전기과) ;
  • 박춘배 (원광대학교 전자재료공학과)
  • Published : 1999.11.20

Abstract

In this paper, DC degradation of ZnO varistor sintered in the atmospheres of nitrogen and oxygen was investigated. The content of $SiO_2$ containing 0.0, 0.2, 0.5 mol% respectively was addicted for the improvement of degradation property. ZnO varistor was fabricated in the special electrical furnace which had the vacuum system. The temperature and the voltage for the DC degradation test were $115{\pm}2^{\circ}C$, $0.85V_{1mA/cm^2}$. The time conditions for this test were 0, 2, 4, 8 hours and Current-voltage analysis is used to determine nonlinear coefficients($\alpha$). Frequency analysis are accomplished for the understanding of electrical properties as DC degradation test. In this experiment, We concluded that nonlinear coefficient decreased as the amount of $SiO_2$ addition increased, but degradation rate coefficient increased as the amount of $SiO_2$ addition increased. Also, degradation test with the analysis of equivalent circuit showed that the degradation phenomenon of ZnO varistor wasn't linearity.

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