Traveling Wave Based Method for Protecting Power Distribution Systems with Distributed Generations

Active distribution systems with high penetration of inverter based distributed generations such as solar generation have characteristics of varied fundamental frequency fault current contributions and lack of zero and negative sequence fault currents. Therefore, existing protection methods based on increase of short circuit currents due to faults may not work well. On the other hand, faults usually generate high frequency transients which are affected little by the output of solar generations. So, harnessing the fault generated high frequency transients may be a promising way to design new, effective protection scheme for inverter based generation dominated distribution systems. This paper presents a novel graph theory and traveling wave based method for protecting power distribution systems. Methods for accurate pinpointing of the fault through use of multiple and single recording of traveling waves are described. Different factors including sampling rates, number of recordings, system configurations, etc., which may affect the performance of the methods, are discussed. Evaluation studies based on simulation are reported.