A Digitalized Implementation of Time-of-Flight Measurement for Cable Fault Location

Abstract:

The major technical difficulty of time domain reflectometry (TDR) based cable fault location lies in the accurate measurement of the time of flight (TOF). The measurement of such time intervals is realized by a digital counter together with a reference clock. Theoretical analysis is established to prove that the resolution can be refined to nanosecond by averaging the counting results from a massive number of repetitive measurements. A microcontroller is used to generate a repetitive step signal in order to perform the repetitive test. 8 MHz clock and 8-bit digital counter are used to measure the time of flight. Experimental results showed that the timing resolution of the counter method is improved to nanosecond using the mean of 30,000 times of measurement results. A portable prototype for cable fault location is made to verify such a configuration. Test results showed that the position of the cable fault can be located with error of less than 0.1m.

• Periodical: Applied Mechanics and Materials (Volumes 336-338)
• Pages: 88-95
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.336-338.88
• Online since: July 2013
• Authors: Jun Hui Yu, Yong Gui Dong
• Keywords: Cable Test, Digital Counter, Time Domain Reflectometry (TDR), Time of Flight

References

[1] J. Shyh-Biau, Y. Chi-Ming, H. Rui-Song, F. Chao-Yi, and Y. Tse-Liang, Instrumentation and Measurement, IEEE Transactions on, vol. 60, pp.735-744, 2011-01-01 (2011).

[2] A. Mantyniemi, T. Rahkonen and J. Kostamovaara, A high resolution digital CMOS time-to-digital converter based on nested delay locked loops, " in Circuits and Systems, 1999. ISCAS , 99. Proceedings of the 1999 IEEE International Symposium on, 1999, pp.537-540.

DOI: 10.1109/iscas.1999.780803

[3] T. K. Lewellen, R. L. Harrison and A. N. Bice, Nuclear Science, IEEE Transactions on, vol. 36, pp.1095-1099, 1989-01-01 (1989).

[4] I. S. Armstrong, H. A. Williams and J. C. Matthews, Accuracy and variability of quantitative measurements using PET with time-of-flight information and resolution modelling, in Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, 2011, pp.4167-4170.

DOI: 10.1109/nssmic.2011.6153797

[5] Shishuang S, Pommerenke D J, Drewniak J L, et al. Instrumentation and Measurement, IEEE Transactions on. 2009, 58(8): 2714-2725.

[6] Smail M K, Pichon L, Olivas M, et al. Magnetics, IEEE Transactions on. 2010, 46(8): 2998-3001.

[7] Information on http: /www. megger. com/cae/products/Index. php.

[8] L. Donghwan, S. Jinho and P. Jaehong, A 16ps-resolution Random Equivalent Sampling circuit for TDR utilizing a Vernier time delay generation, in Nuclear Science Symposium Conference Record, 2003 IEEE, 2003, pp.1219-1223 Vol. 2.

DOI: 10.1109/nssmic.2003.1351912

[9] Kostamovaara J, Myllylä R. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 1985, 239(3): 568-578.

DOI: 10.1016/0168-9002(85)90038-5

[10] Information on http: /www. acam. de/products/time-to-digital-converters/tdc-gpx.

[11] Józef K. Metrologia. 2004, 41(1): 17.

[12] Y. H. M. Thayoob, S. Sulaiman and A. M. Ariffin, Analysis of wave propagation in Time Domain Reflectometry circuit simulation model, in Power and Energy (PECon), 2010 IEEE International Conference on, 2010, pp.276-281.

DOI: 10.1109/pecon.2010.5697590

[13] Information on http: /documents. exfo. com/appnotes/anote168-ang. pdf.

[14] John C. McCosh, U.S. Patent 7, 135, 873 B2. (2006).