한국안전학회지 (Journal of the Korean Society of Safety)

  • 제33권6호
  • /
  • Pages.58-65
  • /
  • 2018
  • /
  • 1738-3803(pISSN)
  • /
  • 2383-9953(eISSN)
한국안전학회 (The Korean Society of Safety)
권호 표지
DOI QR코드

DOI QR Code

자기애자 캡의 금구-시멘트 계면 건전성 평가를 위한 초음파법 활용에 대한 연구

A Study on the Application of Ultrasonic Testing for The Interface Integrity Evaluation between Iron and Cement of Porcelain Insulator Cap

  • 윤영근 (인천대학교 안전공학과) ;
  • 최인혁 (한국전력공사 전력연구원 차세대송변전연구소) ;
  • 손주암 (한국전력공사 전력연구원 차세대송변전연구소) ;
  • 오태근 (인천대학교 안전공학과)
  • 투고 : 2018.12.07
  • 심사 : 2018.12.19
  • 발행 : 2018.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

The life span of the porcelain insulator was made to be 30 years, but currently many of the 154kV NGK porcelain insulators using in Korea are found to have passed the production life. Accidents caused by aged mechanical breakdown can lead to disruption of power supply in some areas, large economic losses, and casualties. Therefore, ultrasonic method, which is one of the non - destructive test methods, is applied as a method for evaluating the integrity of porcelain insulators. In this study, the experiment on the interface of cap was conducted and the difference between the energy difference and the attenuation coefficient of the reflected wave was derived according to the interface state of the steel - cement. The results of this study are expected to be used as the basic data of the ultrasonic testing to evaluate the interface condition of the porcelain insulator cap.

키워드

HOJHB0_2018_v33n6_58_f0001.png 이미지

Fig. 1. Acoustic impedance theory.

HOJHB0_2018_v33n6_58_f0002.png 이미지

Fig. 2. Similar model specimen & porcelain insulator specimen.

HOJHB0_2018_v33n6_58_f0003.png 이미지

Fig. 3. Configuration of experiment equipment.

HOJHB0_2018_v33n6_58_f0004.png 이미지

Fig. 4. Similar model specimen time domain.

HOJHB0_2018_v33n6_58_f0005.png 이미지

Fig. 5. Porcelain insulator specimen time domain.

HOJHB0_2018_v33n6_58_f0006.png 이미지

Fig. 6. Comparison of Up/Umax about two specimen.

HOJHB0_2018_v33n6_58_f0007.png 이미지

Fig. 7. Comparison of attenuation coefficient by formula (6). about two specimen.

HOJHB0_2018_v33n6_58_f0008.png 이미지

Fig. 8. Short-time Fourier transform & Time domain graph.

Table 1. Similar model specimen analysis

HOJHB0_2018_v33n6_58_t0001.png 이미지

Table 2. Porcelain insulator specimen analysis

HOJHB0_2018_v33n6_58_t0002.png 이미지

Table 3. Material properties of specimen

HOJHB0_2018_v33n6_58_t0003.png 이미지

Table 5. Reflection energy ratio

HOJHB0_2018_v33n6_58_t0004.png 이미지

Table 4. Reflection coefficient ratio

HOJHB0_2018_v33n6_58_t0005.png 이미지

Table 6. Comparison of Up/Umax by formula (5) about two specimen

HOJHB0_2018_v33n6_58_t0006.png 이미지

Table 7. Comparison of attenuation coefficient by formula (6) about two specimen - non void

HOJHB0_2018_v33n6_58_t0007.png 이미지

Table 8. Comparison of attenuation coefficient by formula (6) about two specimen - void

HOJHB0_2018_v33n6_58_t0008.png 이미지

참고문헌

  1. I. H. Choi, T. K. Kim, Y. B. Yoon, J. Yi and S. W. Kim, "Lifetime Assessments on 154 kV Transmission Porcelain Insulators with a Bayesian Approach", J. Korean Inst. Electr. Electron. Mater. Eng., Vol. 30, No. 9, pp. 551-557, 2017. https://doi.org/10.4313/JKEM.2017.30.9.551
  2. J. S. T. Looms, "Insulators for High Voltages", IEE Series, 1988.
  3. S. C. Kim and T. Y. Kim, "Application Trends and Technology Trends of Domestic and Foreign Suspension Insulators", The Korean Institute of Electrical Engineers, Vol. 48, No. 12, pp. 22-26, 1999.
  4. I. H. Choi, J. Y. Park and D. H. Kang, " Technology Status of Transmission Insulator", KEPCO Journal on Electric Power and Energy, Vol. 2, No. 3, pp. 365-375, 2016. https://doi.org/10.18770/KEPCO.2016.02.03.365
  5. W. K. Lee, I. H. Choi, K. C. Hwang and H. Y. Choi, "A Study on Life Expectancy Forecast for Porcelain Insulators", The Transactions of the Korean Institute of Electrical Engineers, Vol. 2008, No. 7, pp. 16-18, 2008.
  6. H. G. Jo, D. H. Han and I. H. Choi, "Degradation and Diagnosis Technology of Ultra High Voltage Insulator "Transfer Insulator", Journal of the Korean Institute of Electrical and Electronic Material Engineers, Vol. 17, No. 3, pp. 32-39, 2004.
  7. I. H. Choi, J. H. Choi, Y. H. Jung, D. I. Lee and T. Y. Kim, "Characteristic Test on the Leakage Current of Transmission Insulators", The Transactions of the Korean Institute of Electrical Engineers, Vol. 2003, No. 7, pp. 479-481, 2003.
  8. J. J. Park, "Analysis of Leakage Current Waveforms for Transmission Line Porcelain Insulators due to ESDD Contamination", The Transactions of the Korean Institute of Electrical Engineers, Vol. 61, No. 10, pp. 1461-1470, 2012. https://doi.org/10.5370/KIEE.2012.61.10.1461
  9. J. Y. Cho, S. G. Ji, J. W. Han, H. S. Ahn, T. W. Kim, I. H. Choi and C. Park, "Microstructure based Evaluation of Degradation of Aged Porcelain Suspension Insulators used in Transmission Line", The Transactions of the Korean Institute of Electrical Engineers, Vol. 2017, No.7, pp. 1165-1166, 2017.
  10. L. Chen and J. Q. Wang, "Related Problems in Ultrasonic Detection of Porcelain Insulator", 17th World Conference on Nondestructive Testing, No. 23, pp. 25-28, 2008.
  11. S. I. Park and N. Y. Chung, "Measurement of Crack Length by Ultrasonic Attenuation Coefficients on Interfaces of Al/Epoxy Bonded Dissimilar Materials", The Korean Society of Mechanical Engineers, Vol. 2003, No. 11, pp. 1109-1114, 2003.
  12. N. Y. Chung, "Measurement of Interfacial Crack Length by Ultrasonic Scattering Compensation Depending on Thickness Variations of Bonded Dissimilar Components", Transactions of KSAE, Vol. 14, No. 2, pp. 67-75, 2006.
  13. R. S. Dwyer-Joyce, B. W. Drinkwater and A. M. Quinn, "The Use of Ultrasound in the Investigation of Rough Surface Interfaces", Transactions of the ASME, Vol. 123, pp. 8-16, 2001. https://doi.org/10.1115/1.1330740
  14. P. B. Nagy "Ultrasonic Classification of Imperfect Interfaces", Journal of Nondestructive Evaluation, Vol. 11, No. 3/4, pp. 127-139, 1992. https://doi.org/10.1007/BF00566404
  15. W. Chen, R. Mills and R. S. Dwyer-Joyce "Direct Load Monitoring of Rolling Bearing Contacts using Ultrasonic Time of Flight", Proc. R. Soc. A: Mathematical, Physical and Engineering, Vol. 471, pp. 1-21, 2015.
  16. B. Mojskerc and T. Kek, J. Grum "Pulse-Echo Ultrasonic Testing of Adhesively Bonded Joints in Glass Facades", Journal of Mechanical Engineering, Vol. 62, No. 3, pp. 147-153, 2016. https://doi.org/10.5545/sv-jme.2015.2988
  17. L. W. Schmerr, "Fundamentals of Ultrasonic Nondestructive Evaluation", Plenum Press, 1998.
  18. "Ultrasonic Testing of Materials at Level 2," A Technical Document Issued by the International Atomic Energy Agency, Vienna, Iaea-Tecdoc-462, 1988.
  19. D. R. Kim, S. Y. Lim and S. G. Chung, "A Debonding Detection Technique for FRP/Rubber Interface by Ultrasonic Phase Reversal", The Korean Society of Propulsion Engineers, Vol. 13, No. 2, pp. 9-16, 2009.
  20. J. M. Baik and R. B. Thompson, "Ultrasonic Scattering from Imperfect Interfaces : A Quasi-Static Model", Journal of Nondestructive Evaluation, Vol. 4, No. 3/4, pp. 177-196, 1984. https://doi.org/10.1007/BF00566223
  21. B. C. Woo, S. W. Han and H. G. Cho, "Stress Response of Cement Interface on Manufacturing Process of a Suspension Insulator", The Transactions of the Korean Institute of Electrical Engineers, pp. 1448-1450, 2003.
  22. M. A GONI RODRIGO, "The Ultrasonic Pulse-Echo Immersion Technique And Attenuation Coeeficient Of Particulate Composites", University of Rhode Island Press, London, pp. 65-69, 2013.
  23. Y. G. Young, I. B. Lee, M. H. Sa and T.K. Oh, "A Study on the Statistical Distribution of Ultrasonic Velocities for the Condition Evaluation of Concrete Wide Beam", J. Korean Soc. Saf., Vol. 32, No. 2, pp. 98-104, 2017. https://doi.org/10.14346/JKOSOS.2017.32.2.98
  24. M. H. Sa, Y. G. Young, I. B. Lee and T. K. Oh, "A Study on the Statistical Distribution of Rebound Number and Ultrasonic Pulse Velocity in RC and PSC Concrete Structures", J. Korean Soc. Saf., Vol. 32, No. 4, pp. 53-58, 2017. https://doi.org/10.14346/JKOSOS.2017.32.4.53