Fault location in unearthed 60 kV subtransmission network based on the travelling wave method

In this paper a single-ended travelling wave-based fault location algorithm is presented with reference to HV (60 kV) overhead unearthed operated lines: the time-frequency characteristics of the travelling wave signal are processed by utilising the phase to modal transformation and the continuous wavelet one. The frequency components of the processed signals are used for the travelling wave speed calculation whereas the time components are used for determining the wave arrival times. The fault position is evaluated by combining these two aspects. The proposed approach has been tested in different conditions, in order to assess the method stability: it has been proven insensitive to the fault position, fault resistance and the fault inception angle.