Influence of DGs on the Single-Ended Impedance Based Fault Location Technique

The penetration of Distributed Generation (DG) into electricity distribution systems or the integrated power system such as ship or aircraft power systems present a challenge to fault location techniques. This paper investigates the influence of inverter based DG on a single-ended fault location scheme which uses impedance measurement made from the high frequency content of fault transient. The additional non-fundamental frequency current components contributed from the DG will influence the accuracy of this type of impedance based fault location technique. A single-ended impedance based fault location technique that utilizes the high frequency content (up to 3 kHz) is studied. The study shows that the single-ended method is still able to locate faults with maximum error of 4% compared to the case without DG (which showed a percentage error up to 1%). The study also showed that the DG location has a small influence on the accuracy of the scheme.