Application of S-transform for fault location in combined overhead line and cable distribution networks

This paper illustrates the application of S-transform and continuous wavelet transform (CWT) for fault location in combined overhead line and cable distribution networks. The high frequency transient signals originated by faults are analyzed using S-transform and CWT. The S-transform is found to be applicable in transient based fault location in distribution networks. This technique is an expansion of wavelet transform method and is based on a moving and scalable localizing Gaussian window. 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. The transient voltage signal energy is calculated using S-Transform and CWT. 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 ۳۴-bus test distribution network is simulated in EMTP-RV software and the relevant S-transform and CWT analyses are carried out in MATLAB coding environment

کلیدواژه ها:

Distribution networks ، fault location ، S-transform ، Wavelet transform ، characteristic frequency ، شبکه های توزیع ، جایابی خطا ، تبدیل S ، تبدیل موجک پیوسته ، فرکانس های مشخصه