Discrimination of arcing faults on overhead transmission lines for single-pole auto-reclosure

To block auto-reclosing operation for permanent earth faults on extra-high-voltage transmission lines, an accurate numerical algorithm is developed in this paper. The earth fault location and its nature (arcing or arc-less) are estimated, only using the sequence quantities of the local terminal and their harmonics. The proposed algorithm calculates the amplitude of arc voltage and compares it with a given threshold value; then, decision is made if it is transient or not. A square wave arc model is considered to represent the long electric arc in the free air. One main contribution of the algorithm is its independence from the remote terminal information such as phase difference and infeed current. The successful simulation results using the square wave and dynamic arc models show that this simple and powerful algorithm can be effectively utilized for implementing a single-pole auto-reclosing scheme.