Industrial sensors and control--The basics--Part VII

POWER LINE FAULT-DETECTION SYSTEM FOR POWER GENERATION AND DISTRIBUTION INDUSTRY

In power distribution lines, faults such as short circuits, ground faults, and lightning strikes on the conductors must be detected in a very short time to prevent damage to equipment and power failure, and to enable quick repair. If the transmission line is divided in sections and a current or magnetic-field sensor is mounted in each section, a faulty section can be determined by detection of a change of the level and phase of the current on the power line. A system was developed as a hybrid optical approach to a fault-locating system that detects the phase and current difference between two current transformers on a composite fiber-optic ground wire (OPGW) wherein, due to induction, current is constantly passing (Fig. 6.34).

The signal from a local electrical sensor, powered by solar cells and batteries, is transmitted over a conventional optical-fiber communication link. By three-wavelength multiplexing, three sensor signals can be transmitted over a single fiber. Seven sensors, three at each side of a substation and one at the substation itself, can monitor one substation on the power line, using one fiber in the OPGW.

Another system uses current transformers to pick up lightning current and thus detect lightning strikes. The signal is transmitted to a central detection point using the OPGW. Every sensor has its own OPGW fiber. This system is on a 273-kV power line in Japan.

The OPGW opens the possibility for using all kinds of sensors along the transmission line. These sensors may not only be for locating faults, but also for monitoring structural integrity. The use of optical time-domain reflectometry combined with passive intrinsic (distributed) sensors along the OPGW has future potential for providing a convenient and powerful monitoring method for power lines.

REFERENCES

1. Bailey Control Systems, Wickliffe, Ohio.

2.    Bartman, R. K., B. R. Youmans, and N. M. Nerheim. “Integrated Optics Implementation of a Fiber Optic Rotation Sensor: Analysis and Development,” Proc. SPIE 719, 122–134.

3. Berthold,J.W.,“IndustrialApplicationsofOpticalFiberSensors,”FiberOpticandLaserSensorsIII, Proc. SPIE 566, 37–44.

4. Carrol, R., C. D. Coccoli, D. Cardelli, and G. T. Coate, “The Passive Resonator Fiber Optic Gyro and Comparison to the Interferometer Fiber Gyro,” Proc. SPIE 719, 169–177 (1986).

5. Chappel, A. (ed.), Optoelectronics—Theory and Practice, McGraw-Hill, New York, 1978.

6.    Crane, R. M., A. B. Macander, D. W. Taylor, and J. Gagorik, “Fiber Optics for a Damage Assessment System for Fiber Reinforced Plastic Composite Structures,” Rev. Progress in Quantitative NDE, 2B, Plenum Press, New York, 1419–1430 (1982).

7.    Doeblin, E. O., Measurement Systems—Application and Design, 4th ed., McGraw-Hill, New York, 1990.

8. Fields, J. N., C. K. Asawa, O. G. Ramer, and M. K. Barnoski, “Fiber Optic Pressure Sensor,” J. Acoust. Soc. Am. 67, 816 (1980).

9. Finkelstein, L., and R. D. Watts, “Fundamental of Transducers—Description by Mathematical Models,” Handbook of Measurement Science, vol. 2, P. H. Sydenham (ed.), Wiley, New York, 1983.

10. Friebele, E. L. and M. E. Gingerich, “Radiation-Induced Optical Absorption Bands in Low Loss Optical Fiber Waveguides,” J. Non-Crust. Solids 38(39), 245–250 (1980).

11. Henze, M., “Fiber Optics Temperature and Vibration Measurements in Hostile Environments,” Technical Material, ASEA Research and Innovation, CF23-1071E (1987).

12. Hofer, B., “Fiber Optic Damage Detection in Composite Structure,” Proc. 15th Congress. Int. Council Aeronautical Science, ICAS-86-4.1.2, 135–143 (1986).

13. Kapany, N. S., Fiber Optics, Principles and Applications, Academic Press, London, 1976.

14. Lagakos, N., et al., “Multimode Optical Fiber Displacement Sensor,” Appl. Opt. 20, 167 (1981).

15. Liu, K., “Optical Fiber Displacement Sensor Using a Diode Transceiver,” Fiber Optic Sensors II, A. M. Sheggi (ed.), Proc. SPIE 798, 337–341 (1987).

16. Mizuno, Y., and T. Nagai, “Lighting Observation System on Aerial Power Transmission Lines by Long Wavelength Optical Transmission,” Applications of Fiber Optics in Electrical Power Systems in Japan, C.E.R.L. Letterhead, paper 5.

17.   Mori, S., et al., “Development of a Fault-Locating System Using OPGW,” Simitomo Electric Tech. Rev. 25, 35–47.

18. Norton, H. N., Sensors and Analyzer Handbook, Prentice-Hall, Englewood Cliffs, N.J., 1982.

19. Neubert, H.K.P., Instrument Transducers, 2d ed., Clarendon Press, Oxford, 1975.

20. Ogeta, K., Modern Control Engineering, 2d ed. Prentice-Hall, Englewood Cliffs, N.J., 1990.

21.   Petrie, G. R., K. W. Jones, and R. Jones, “Optical Fiber Sensors in Process Control,” 4th Int. Conf. Optical Fiber Sensors, OFS’86, Informal Workshop at Tsukuba Science City, VIII I–VIII 19, (1986).

22. Place, J. D., “A Fiber Optic Pressure Transducer Using a Wavelength Modulation Sensor,” Proc. Conf. Fiber Optics ’85 (Sira), London, (1985).

23.   Ramakrishnan, S., L. Unger, and R. Kist, “Line Loss Independent Fiberoptic Displacement Sensor with Electrical Subcarrier Phase Encoding,” 5th Int. Conf. Optical Fiber Sensors, OFS ’88, New Orleans, 133–136 (1988).

24. Sandborn,V.A.,ResistanceTemperatureTransducers,MetrologyPress,FortCollins,Colo.,1972.

25.   Scruby, C. B., R. J. Dewhurst, D. A. Hutchins, and S. B. Palmer, “Laser Generation of Ultrasound in Metals,” Research Techniques in Nondestructive Testing, 15, R. S. Sharpe (ed.), Academic Press, London, 1982.

26. Tsumanuma, T., et al., “Picture Image Transmission-System by Fiberscope,” Fujikura Technical Review 15, 1–10 (1986).

27. Vogel, J. A., and A.J.A. Bruinsma, “Contactless Ultrasonic Inspection with Fiber Optics,” Conf. Proc. 4th European Conf. Non-Destructive Testing, Pergamon Press, London, 1987.

28. Yasahura, T., and W. J. Duncan, “An Intelligent Field Instrumentation System Employing Fiber Optic Transmission,” Advances in Instrumentation, ISA, Wiley, London, 1985.

About the Author

Sabrie Soloman, Ph.D, is the Founder, Chairman and CEO of American SensoRx, Inc.

Excerpted from Sensors Handbook, 2nd Edition by Sabrie Soloman (McGraw-Hill; 2010) with permission by McGraw-Hill.

If you liked this article, go to the Industrial Control DesignLine home page for the latest in industrial control design, technology, trends, products and news.

Also, get a weekly highlights update delivered directly to your inbox by signing up for our weekly industrial control newsletter here.