Power Transmission Line Fault Diagnosis Using Discrete Wavelet Transform

In this paper, a new method for detecting short-circuit faults on transmission lines using discrete wavelet transform (DWT) is proposed. This work presents a single-ended based technique where the three-phase current data on bus 1 is measured and decomposed to level 6 by DWT and then the detail coefficients are calculated which are also compared with thresholds to detect faults and classify faults. In order to verify the proposed ideas, various short-circuit fault simulations are performed on 230 kV, 50 Hz, and 100 km transmission lines in the MATLAB/Simulink environment. The performance of the proposed method is analyzed through various case studies with different fault locations and fault types, and the simulation results prove the efficiency of the proposed algorithm

I. Introduction

Transmission lines play an important role in power systems as they transfer power from a source to a load. Transmission line failures can disrupt power continuity and damage the equipment. Therefore, there is a need to quickly and accurately identify and clear the faults to restore system performance. Correct information about the fault type is a crucial factor in protecting the correct functioning of the system. One type of these faults is short circuit, which can be divided into single-phase L-G (PhA to ground, PhB to ground, PhC to ground), two-phases short-circuit 2L to ground,(PhAB-gnd, PhBC-gnd, PhAC-gnd), double phase-to-ground short-circuit 2L ungrounded (Pha-b, Phb-c, Pha-c) and three-phase short circuit 3L (Pha-b-c) [1].