Earthfault-Localisation in Compensated 20-kV-Networks Based on Travelling-Waves

Due to today's increased demands on grid operation management, new methods for earth fault localization and detection are needed. The fault localisation should be performed as quickly as possible and under the condition, that the fault current at the fault location will not be significantly increased. Fault location method based on the travelling wave (TW) theory is already in use in some countries for transmission networks, but there exist no realisations for the distribution networks. At the transmission level the connections between substations are more or less long homogenous point-to-point connections. The structure of the compensated distribution networks is completely different. They are looped or open-looped with additional trees, mixture of overhead-lines and cables and with a lot of secondary substations and distribution transformers. This paper presents a feasibility study under which conditions travelling waves can be used in a compensated distribution-network and what is the impact of new developments in electronics, for example faster microprocessors and faster analogue-digital-converters (ADC). This paper is presenting the first results of this feasibility study.