Travelling-wave-based on-line fault location scheme for 110kV power cable

This paper presents a novel wavelet-based fault location scheme for 110kV cable when the digital fault recorded data are available at the two terminals of each cable. Three phase current signals are decoupled into two aerial modes and one zero mode with the phase-mode transformation. The theory of wavelet singularity detection is applied to extract the arrival time of the travelling wave from the aerial mode which are necessary for fault location. The proposed scheme can determine the fault location without the support of GPS and has the ability to eliminate the uncertain factor including wave velocity and transition impedance. Characteristics of the proposed fault location scheme are studied with some simulation cases by using PSCAD/EMTDC. The results indicate that the proposed scheme has acceptable accuracy for fault location.