Medium-voltage distribution feeders in closed-loop arrangement – neutral point grounding

Abstract

This paper deals with medium-voltage networks where the closed-loop arrangement of feeders is used to improve the reliability of power supply. The paper focuses on the neutral point grounding in the medium-voltage loops. They are established by closing feeders, supplied form different transformers, in closed-loop arrangement. It is shown in the case when the neutral points of transformers supplying the feeders are grounded, the fault current at the fault location can be doubled, without to influence the neutral point current, which could cause safety problems.