A philosophy and algorithms for extinguishing earth fault arcs in suppressed medium voltage networks

The compensation of earth fault current in medium voltage power networks can be carried out either centrally or by using more cost-effective decentralized compensation. This paper introduces a novel cost-effective principle for increasing the compensation degree and selecting the tripping range of earth fault relays in originally partially compensated or isolated power systems. This has an essentially positive effect on the reduction of short interruptions to customers. Earth faults in compensated systems are simulated by the ATP version of the well-known EMTP program and the results are compared to field measurements. Conditions in radially operated rural 20 kV overhead line networks are considered