A comparison between S-transform and CWT for fault location in combined overhead line and cable distribution networks

Considering the complex topology of distribution networks and their important application, finding an effective fault location algorithm is mandatory. This paper discusses and compares the effectiveness of continuous wavelet transform (CWT) and S-transform for the fault location in combined overhead line and cable distribution networks. Taking into account this fact that the signal energy of faults has high amplitude around certain frequencies, the fault location can be identified considering the relationship between these frequencies and so-called path characteristic frequencies related to the fault traveling waves. In order to demonstrate the effectiveness of the proposed method, the distribution networks with only overhead lines, as well as a combined system (consisting of the overhead lines and underground cables) have been studied. The IEEE 34-bus test distribution network is simulated in EMTP-RV software. The relevant S-transform and CWT analyses are carried out in MATLAB coding environment.