Detection and Classification of Transmission Line Faults using Discrete Wavelet Transforms in the presence of STATCOM

Abstract

This paper presents, detection of transmission line faults by applying discrete wavelet transforms when the FACTS (Flexible alternating current transmission system) controller present. With the presence of FACTS device, the actual impedance of system will change which makes very hard to detect faults. Wavelet Transform is a mathematical tool which is used for analysis of a signal of high frequency components to detect and to categorize the faults which occurred on transmission line by extracting the transients of line currents. Three- phase currents at both ends are monitored with the help of daubechies-10 as mother wavelets up to level-5. By adding detail coefficients of local end and remote end of a line, faults index is calculated and it is compared with the threshold value of a signal of healthy phase. The transmission line model is tested in the presence and absence of STATCOM in MATLAB/SIMULINK 2020b to detect and classify the various classes of faults such as single line-to-ground (L-G) faults, line-to-line (L-L) faults, double line-to-ground (L-L-G) and three-phase faults(L-L-L and L-L-L-G).