Development of a Wavelet-ANFIS based fault location system for underground power cables

Abstract

In the past decade, electricity demand has increased rapidly in metropolitan areas. All over the world, large scale underground power cable installations networks are replacing overhead transmission lines due to environmental concerns in densely populated areas. Underground cable systems are manufactured to have long life with reliability. However, the useful life span of these cables is not infinite. The increase in failure rates and system breakdowns on older underground power cables are now adversely impacting system reliability and many losses involved; therefore it is readily apparent that necessary action has to be taken to manage the consequences of this trend. In this paper, a method that combines wavelets and Neuro-fuzzy technique for fault location and identification is proposed. A 10km, 34.5KV, 50Hz power transmission line model was developed and different faults and locations simulated, and then certain selected features of the wavelet transformed signals were extracted to develop an ANFIS for fault location. Comparison of the ANFIS output values and the actual values show that the percentage error was established to be less than 1%. Thus, it can be concluded that the wavelet-ANFIS technique is accurate enough to be used in identifying and locating underground power line faults.