Safety aspects and novel technical solutions for earth fault management in MV electricity distribution networks

Abstract

The paper considers the safety aspects of earth fault management and needs for indication and location of high-resistance earth faults in medium voltage (MV) electricity distribution networks. Applying the methods available the safety of electricity distribution can be improved and the number and duration of outages to customers can be reduced. Methods for very high-resistance earth fault identification and location in neutral isolated or compensated distribution systems have been developed in Tampere University of Technology. These indication methods are able to detect and locate faults up to some hundreds of kilo-ohms. The indication methods have proven to be very appropriate for the implementation and the results from the field installation and field experiments are promising. Aspects for achieving a compromise between the safety and reliability of the electricity distribution are also highlighted.