Switched and Polyphase Distance Relays

Reduction of Measuring Units—Automatic Switching Schemes—Polyphase Distance Relays—Phase and Amplitude Comparators—Analysis of Polyphase Comparators
  • A. R. van C. Warrington


The early time-distance schemes had the merit of simplicity. Since the operating time was proportional to the distance of the fault from the relay only one relay was necessary per phase, but the clearing time was high for faults near the end of the protected section (fig. 6.1). The stepped time-distance scheme was introduced in Canada in 1925 by Paul Ackerman. It had the advantage of reducing the overall clearing time by the shaded areas in fig. 6.1 and is now universally used.


Fault Detector Phase Comparator Protective Relay Ground Fault Zero Sequence 
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. 10.
    Hoard, B. V. ‘An Improved Polyphase Directional Relay’, Transactions A.I.E.E., 60, May, 1941, pp. 24–28. Disc, p. 633.Google Scholar
  2. 32.
    McConnell, A. J. ‘A Single Element Polyphase Directional Relay’, Transactions A.I.E.E., 56, No. 1, 1937, pp. 77–80 and 113; No. 8, pp. 1025–1028.CrossRefGoogle Scholar
  3. 52.
    Dodds, G. B. and Marter, W. E. ‘Reactance Relays Discriminate between Load-Transfer Current and Fault Currents on 2,300-volt Station Service Generator Bus’, Transactions A.I.E.E., 71, Part III, 1952, pp. 1124–1128. Disc, p. 1128.Google Scholar
  4. 66.
    Warrington, A. R. van C. ‘Control of Distance Relay Potential Connections’, A.I.E.E., Electrical Engineering, 53, 1934, pp. 206–213. Disc, pp. 465–466 and 617.Google Scholar
  5. 67.
    Audlin, L. J. and Warrington, A. R. van C. ‘Distance Relay Protection for Subtransmission Lines made Economical’, A.I.E.E. Paper No. 43–92, May, 1941Google Scholar
  6. 69.
    Feist, P. K. ‘An Analysis of Compensated Polyphase Relays Using the Circle Diagram’, Electrichestvo, 1957, No. 9, pp. 31–35.Google Scholar
  7. 104.
    Baldwin, C. J. and Goffard, B. N. ‘An Analysis of Polyphase Directional Relay Torques’, Transactions A.I.E.E., 72, Part III, 1953, pp. 752–759.Google Scholar
  8. 108.
    Losev, S. B. and Cherman, A. B. ‘Study of 3-phase Directional Impedance Relays under Short Circuit Conditions’.Google Scholar
  9. 133.
    Salzmann, A. ‘Cross Country Faults seen by Protective Relays in Resonant Neutral Earthed Transmission Systems’, Electrical Energy, 1, No. 16, December, 1957, pp. 494–500.Google Scholar

Copyright information

© Albert Russell van Cortlandt Warrington 1968

Authors and Affiliations

  • A. R. van C. Warrington
    • 1
  1. 1.The English Electric Company LimitedStaffordUK

Personalised recommendations