Detection of the intermittent earth faults in compensated MV network

The experience acquired from the Polish medium voltage power distribution networks shows the unreliability of the localization criterions applied to the intermittent earth faults. It results from the lack of stability and low power level of the measuring signals falling often down below the protection´s start-up level. In the paper, a new adaptive algorithm based on the wavelet analysis enabling detection of specific dynamics of the measuring signal during intermittent earth faults is presented. The algorithm was analyzed utilizing the signals generated in the EMTP program package.