DOI QR코드

DOI QR Code

A Study on the Dielectric Characteristics of GFRP in LN2 under Lightning Impulse Voltage According to Pressure

액체질소 내에서 뇌 임펄스전압에 대한 압력별 GFRP의 절연파괴 특성 분석

  • 홍종기 (한국교통대 전기공학과) ;
  • 허정일 (한국교통대 전기공학과) ;
  • 남석호 (한국교통대 전기공학과) ;
  • 강형구 (한국교통대 전기공학과)
  • Received : 2012.09.11
  • Accepted : 2012.09.24
  • Published : 2012.10.01

Abstract

A study on the dielectric characteristics of the Glass Fiber Reinforced Plastic (GFRP) is important for designing a reliable high voltage superconducting machines such as transmission superconducting fault current limiters, superconducting cables, and superconducting transformers. In this paper, dielectric experiments of the GFRP under lightning impulse voltage are conducted in liquid nitrogen($LN_2$) according to various experimental conditions such as the thicknesses of the GFRP, the diameters of electrode systems and the pressures. The dielectric characteristics of the GFRP are analyzed by using a Finite Elements Method(FEM) according to various field utilization factors. It has been reported that the electrical insulation design of the GFRP would be conducted by considering the mean electric field intensity($E_{mean}$) distributed inside the GFRP. In this study, it is found that the dielectric performance of the GFRP could be explained by not only $E_{mean}$ but also the maximum electric field intensity ($E_{max}$). Finally, the empirical formulae of the GFRP to estimate an electrical breakdown voltage at sparkover under the lightning impulse condition are deduced. It is expected that the presented experimental results in this paper are helpful to design electrically reliable high voltage superconducting machines using the GFRP as an insulation material.

Keywords

Dielectric characteristics;Electrical breakdown voltage;Flashover voltage;Sphere to plane electrode system;Utilization factor

Acknowledgement

Supported by : National Research Foundation of Korea (NRF)

References

  1. Seok Ho Nam, Hyoungku Kang, "A study on the Lightning Impulse Dielectric Characteristics of Air for the Development of Air-Insulated High Voltage Apparatuses", Journal of the Korea Institute of Electrical Engineers, Vol. 60, No. 5, pp. 1005-1009, 2011 https://doi.org/10.5370/KIEE.2011.60.5.1005
  2. Jin Bae Na, Hyoungku Kang, Young Jin Hwang, Seong Eun Yang, Dong Keun Park, Duck Kweon Bae, Tae Kuk Ko, "Experimental Study on the Electrical Breakdown Characteristics of Sub-cooled Liquid Nitrogen for Designing a High Voltage Superconducting Machine", IEEE Trans. Applyed Superconductivity, Vol. 20, No. 3, pp. 1662-1666, June, 2010 https://doi.org/10.1109/TASC.2010.2041649
  3. Jeong Il Heo, Jonggi Hong, Seokho Nam, Hyoungku Kang, "Analysis on the insulation characteristics of SMC under AC voltage", Journal of the Korea Institute of Electrical Engineers Sumer Conference 2012, 12-p-029
  4. Jong Il Kim, "High voltage discharge plasma theory and applications", Doseo publication intervision, 2004.
  5. Li feng, Yang Woo Yoo, Dong Kyu Kim, Bok Hee Lee "Dielectric Characteristics of SF6 and Dry-Air Gases under Lightning Impulse Voltage", Journal of the Korea Institute of Illuminationg and Electrical Installation Engineers, Vol. 24, No. 8, pp. 142-149, 2010 https://doi.org/10.5207/JIEIE.2010.24.8.142
  6. J. B. Na, T. K. Ko, H Kang, B. Y. Seok, and T. J. Kim, "Analytical and Experimental studies on Dielectric Characteristics of High Voltage Superconducting Machines in Liquid Nitrogen", Journal of the Korea Institute of Applied Superconductivity and Cryogenics, Vol. 13, No. 1, pp. 46-50, 2011 https://doi.org/10.9714/psac.2011.13.1.046
  7. Hyoungku Kang, Tae Kuk Ko, "A Study on the Dielectric Characteristics of Insulation Gases for a Sub-cooled Liquid Nitrogen System", Journal of the Korea Institute of Applied Superconductivity and Cryogenics, Vol. 12, No. 1, pp. 52-55, 2010