On-line fault location scheme for power cable based on Arc characteristic

In this paper, a novel fault location scheme for 110kV XLPE cable based on wavelet analysis is presented. Three phase fault currents are collected by the fault recorders installed at the two terminals of the cable. One zero mode and two aerial modes are obtained after the recorded current signals are decoupled with phase-mode transformation. The arrival time of the travelling wave can be identified precisely with the α aerial mode by using the wavelet singularity detection technology. The proposed algorithm can position the fault without GPS and is independent of the wave velocity and fault transition impedance. This will help to solve the problem of cable changing parameters, especially the change of wave velocity due to the changing relative permittivity with age. Arc characteristics are considered by establishing the Cassie arc model. Several simulation cases are studied by using PSCAD/EMTDC and the results indicate the proposed scheme is feasible and reliable for application.