A new high impedance fault detection scheme: Fourier based approach

High impedance faults (HIFs) are part of the most common faults in distribution power system. The randomness, non-linearity and unstable nature of these faults have resulted in false detection and a growing concern, due to the involvement of electrical arcs. Contrary to typical power system faults, HIFs are more likely to result in casualties and therefore, are treated with grave importance. Low current magnitude is witnessed to be overcurrent relays biggest weakness and the main reason of conventional methods failure. In the presented paper, a new Fourier based detection scheme has been proposed. By designing two independent parallel algorithms, focusing on abnormal conditions and HIF signatures, this method benefits from simplicity, low computational burden and high accuracy in comparison to other conventional methods. Simulation of an IEEE standard distribution system has provided proof to this claim. Needles of extra equipment installation has also made the proposed method financially reasonable.