An algorithm based on discrete wavelet transform for fault detection and evaluation of the performance of overcurrent protection in radial distribution systems

This paper presents a fault detection method for distribution systems. The method is based on discrete wavelet transform and uses the currents of the feeder per phase, monitored only in the substation, as basis for analysis. The proposed method takes advantage of the special properties of wavelet transform to differentiate waves signature produced by a system under normal conditions, under disturbs related to power quality and under faults involving short-circuits conditions. An Algorithm based on discrete wavelet transform is used to detect, classify and locating the faults in the moment they occur. The main application of the software is to assist the operation during a fault, and supervise the protection system. Simulation results obtained by using ATP/EMTP for a 282-bus non-transposed real feeder are included for demonstration of the proposed method. The results show that the algorithm is effective for diagnosing all types of faults involving short-circuits and it has great potential for on-line applications.