An algorithm for directional earth-fault relay with no voltage inputs

作者：Stojanovic Zoran N^*; Djuric Milenko B

来源：Electric Power Systems Research, 2013, 96: 144-149.

DOI：10.1016/j.epsr.2012.11.004

• Digital relaying
• Directional earth-fault relay
• Isolated neutral network
• Relay protection
• Phase comparator
• Directional element

In this paper an algorithm for directional earth-fault relay without voltage inputs is presented. This relay is intended for use in isolated neutral networks. For a reference quantity the algorithm does not use the zero sequence voltage, but phase currents since in isolated neutral system they vary only slightly when a phase-to-earth fault occurs. Instead of the phase angle between the zero-sequence voltage and current phasors, the integral of the product of the phase and zero-sequence current over one-half period of the signals is calculated. For this reason the algorithm has high speed of response. The algorithm detects not only the line containing a phase-to-earth fault but also the faulted phase.

• 出版日期2013-3