Digital communications

  • C. Christopoulos
  • A. Wright


Many protection arrangements require some means of communication. Examples are, distance schemes with some form of intertripping and phase comparison in differential current protection schemes. For a long time, communications were based on lines leased from the Post, Telephone and Telecommunications (PTT) authorities, Power-Line Carrier (PLC) systems, or microwave channels. Advances in information technology in recent years have meant that it is now possible to employ digital communication networks of high capacity for protection control as well as data and voice channels. In fact, technological changes mean that the differences between voice, data and video communications are blurred as are the differences between data communications and data processing in single- and multiprocessor systems. There is now a plethora of information about the power system, potentially of importance to protection, which can now share data and communications with the control and management functions of a network. The rate at which this sharing and interdependence will increase and what final level it will reach is difficult to foresee. Undoubtedly, long term reliability of protection schemes relying on communications has depended on the communication system and therefore the introduction of new communications technologies deeper into protection procedures has to be examined carefully so that system security and dependability is maintained at high levels. It is now essential that the protection engineer is aware of digital communications issues so that he or she can influence the development of the communications network, take advantage of the possibilities that it offers and maintain the high integrity of the protection relays designed according to the principles presented in previous chapters. The purpose of this chapter is to introduce the basic principles of digital communications and their use in protection.


Digital Communication Transmission Medium Cyclic Redundancy Check Electromagnetic Compatibility Maximum Data Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Stallings, W. (1994) Fourth edn, Data and Computer Communications, Macmillan.Google Scholar
  2. 2.
    Halsall, F. (1994) Fourth edn, Data Communications, Computer Networks and Open Systems, Addison-Wesley, NY.Google Scholar
  3. 3.
    Tanenbaum, A. S. (1996) Third edn, Computer Networks, Prentice-Hall, NJ.Google Scholar
  4. 4.
    CIGRE Report (1991) Application of Wideband Communication Circuits to Protection — Prospects and Benefits, Working Group 05 of Study Committee 34.Google Scholar
  5. 5.
    Aggarwal, R. and Moore, P. (1993) Digital communication for protection, Part 1 — General principles, Power Engng J., pp. 281–287.Google Scholar
  6. 6.
    Christopoulos, C. (1995) Principles and Techniques of Electromagnetic Compatibility, CRC Press, Boca Raton.zbMATHGoogle Scholar
  7. 7.
    Christopoulos, C. (1992) Electromagnetic compatibility — Part I (General principles), IEE Power Engng J., 6, 89–94.CrossRefGoogle Scholar
  8. 8.
    Christopoulos, C. (1992) Electromagnetic compatibility — Part II (Design principles), IEE Power Engng J., 6, 239–247.CrossRefGoogle Scholar
  9. 9.
    Aggarwal, R. and Moore, P. (1994) Digital communication for protection, Part 3 — Fibre optics, Power Engng J., 241–246.Google Scholar
  10. 10.
    IEE Tutorial on Modern Techniques for Power Systems Protection,University of Nottingham, 24 March 1997.Google Scholar
  11. 11.
    Hall, I. J. (1993) Performance assessment of digital teleprotection systems, Proc. 5th Int. Conf. on Developments in Power System Protection, IEE Conf. Publication 368. York, 30 Mar.-1 Apr., 1993, 1–4.Google Scholar
  12. 12.
    Hall, I. J. and Potts, S. (1996) Experience in the use of digital communication links for protection, CIGRE Report 35/34–03.Google Scholar
  13. 13.
    Selga, J. and Rivera, J. (1981) HDLC Reliability and the FRBS Method to Improve it, Seventh Data Comms. Symp. Proc., Mexico City, Oct. 27–29, 260–267.Google Scholar
  14. 14.
    Guide on EMC in Power Plants and Substations,prepared by CIGRE Group 36.04, April 1997.Google Scholar

Further Reading

  1. CIGRE WG 34.03, (1996), Communication requirements in terms of data flow within substations, Final Report 96–12–01.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • C. Christopoulos
    • 1
  • A. Wright
    • 1
  1. 1.University of NottinghamNottinghamUK

Personalised recommendations