volume | PIER Journals

Abstract

The number of composite insulators used in power transmission lines increases year by year. To detect and assess the aging status accurately concerns the security and stability of the power system. In order to achieve nondestructive testing of the sheds of composite insulators, a unilateral mini Nuclear Magnetic Resonance (NMR) sensor is proposed in this paper. The design of the magnet body and the optimization of the RF coil are presented. The Carr-Purcell-Meiboom-Gill (CPMG) sequence was employed to record the 1H relaxation curves of the sheds of three composite insulators from 110 kv lines with different service years. The curves were fitted to both single exponential function and inverse Laplace transformation functions. The results demonstrate that an increase of service year of the insulator results in a decrease of the effective transverse relaxation time (T_2eff). It is indicated that the sensor has a potential to assess the aging status of the composite insulators.

1. Looms, J. S. T., "Insulators for high voltages,", The Institution of Engineering and Technology, 1988.
doi:10.1109/94.798114 Google Scholar

2. Hackam, R., "Outdoor HV composite polymeric insulators," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 6, No. 5, 557-585, 1999. Google Scholar

3. Cui, J. L. and Z. Y. Su, "The application and prospect of silicone rubber composite insulators in China," China Power, Vol. 32, No. 1, 38-41, 1999. Google Scholar

4. Yong, J., Q. H. Shen, F. Q. Zhao, et al. "The application and prospect of silicone rubber composite insulators in China," China Electric Power, Vol. 32, No. 1, 38-41, 1990.
doi:10.1007/s11431-007-0053-x Google Scholar

5. Amin, M., M. Akbar, and M. Salman, "Composite insulators and their aging: An overview," Science in China Series E: Technological Sciences, Vol. 50, No. 6, 697-713, 2007. Google Scholar

6. Song, W., L. J. Zhao, C. R. Li, et al. "The development of online detection technology of composite insulators ," High Voltage Engineering, Vol. 31, No. 5, 30-32, 2005. Google Scholar

7. Hui, H., S. Wang, B. Yang, et al. "Research on the evaluation methods of the operating status and aging characteristics of composite insulators," Shaanxi Electric Power, Vol. 40, No. 1, 64-66, 2012. Google Scholar

8. Tu, Y. P., C. H. Chen, Y. L. Tong, et al. "The evaluation methods of aging characteristics of operating composite insulators," High Voltage Engineering, Vol. 38, No. 10, 2522-2527, 2012. Google Scholar

9. Yan, B. and Z. H. Wang, "The analysis of the aging properties of silicone rubber composite insulators materials," Insulation Materials, Vol. 4, 58-60, 2009. Google Scholar

10. STRI Guide 92/1 "Hydrophobicity classification guide,", Swedish Transmission Research Institute, 1992. Google Scholar

11. Yang, Z. G., S. H. Wang, F. C. Lv, et al. "Design and application of leakage current measurement system for polluted insulator," Electric Power Science and Engineering, Vol. 26, No. 1, 14-18, 2010. Google Scholar

12. Chen, W. G., W. P. Wang, and Q. Xia, "Research on multi-fractal characteristics of leakage current for contamination discharge of insulators," Transactions of China Electro-technical Society, Vol. 28, No. 1, 50-56, 2013.
doi:10.1109/TDEI.2004.1324357 Google Scholar

13. Kumagai, S. and N. Yoshimura, "Leakage current characterization for estimating the conditions of ceramic and polymeric insulating surfaces," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 11, No. 4, 681-690, 2004. Google Scholar

14. Bai, H., J. L. Hu, J. Li, et al. "Hydrophobicity evaluation of composite insulators using the dynamic contact angle," High Voltage Engineering, Vol. 36, No. 12, 3021-3027, 2010. Google Scholar

15. Tong, Y. L., "Study on the aging characteristic of composite insulator based on TSC,", North China Electric Power University Master’s Degree Thesis, Jun. 2011. Google Scholar

16. Liang, Y., L. J. Ding, and C. R. Li, "Primary research on the diagnosis of aging silicone rubber insulator using thermally stimulation current," Proceedings of the CSEE, Vol. 27, No. 21, 7-12, 2007. Google Scholar

17. Zhang, H., Y. P. Tu, and Y. L. Tong, "Study on aging characteristics of silicone rubber shades of composite insulators based on TSC test," Proceedings of the CSEE, Vol. 32, No. 19, 169-174, 2012. Google Scholar

18. Blumich, B., S. Anferova, F. Casanova, K. Kremer, J. Perlo, and S. Sharma, "Unilateral NMR: Principles and applications to quality control of elastomer products," Testing and Measuring, Vol. 7-8, 346-349, 2004.
doi:10.1016/j.pnmrs.2007.10.002 Google Scholar

19. Blumich, B., J. Perlo, and F. Casanova, "Mobile single-sided NMR," Progress in Nuclear Magnetic Resonance Spectroscopy, Vol. 52, 197-269, 2008.
doi:10.1007/s00723-013-0489-z Google Scholar

20. Xu, Z., S. J. Zhao, and P. Guo, "A portable sensor used for assessing the aging status of silicone rubber insulator," Applied Magnetic Resonance, Vol. 44, 1405-1417, 2013. Google Scholar

21. Xu, , Z., K. K. Meng, and J. Y. Cheng, "Highly uniform singled-sided portable NMR sensor and its application in assessing the aging level of silicone rubber insulators," International Journal of Applied Electromagnetic Mechanics, Vol. 47, 777-790, 2015. Google Scholar

22. Hoult, D. I. and R. E. Richards, "The signal-to-noise ratio of the nuclear magnetic resonance experiment," Journal of Magnetic Resonance, Vol. 24, No. 1, 71-85, 1976. Google Scholar

23. Haacke, E. M., R. W. Brown, M. R. Thompson, et al. Magnetic Resonance Imaging: Physical Principles and Sequence Design, A John Wiley and Sons, New York, 1999.

24. Hurlimann, M. D., "Well logging," Encyclopedia of Magnetic Resonance, John Wiley & Sons Ltd., 2012.
doi:10.1016/0010-4655(82)90173-4 Google Scholar

25. Provencher, S. W., "A constrained regularization method for inverting data represented by linear algebraic or integral equations," Computer Physics Communications, Vol. 27, 213-227, 1982. Google Scholar

Dr. Yunfeng Xia

Dr. Zheng Xu

Dr. Jianhua Huang

Dr. Jianhua Lin

Dr. Dengjie Yu