Decentralized earth fault selectivity using transient front slopes for unearthed MV networks

In this paper, a transient-based selectivity function is introduced for identifying the faulty section due to earth faults. The proposed selectivity procedure enhances the earth fault management in unearthed/compensated MV networks using decentralized control. The faulty section is discriminated by evaluating relative polarities, at each section terminals of front slopes, created by the earth fault occurrence. The fault surge slopes are extracted by differentiating the residual current waveforms. A threshold value is evaluated to localize the polarity measuring. The outline of integrating the proposed selectivity function is discussed with the decentralized control.