Fault Detection of Underground Cable Using FFT in Kurdistan Area

Compared to circuits with greater nominal voltages, the modeling and computation of a single phase-to-earth fault of the distribution for underground cables have unique characteristics. This work presents a mathematical analysis and modeling of 3-phase, open circuit, and single line-to-ground cables for the Azadi distribution substation lines. The feature of increased harmonic amplification of individual frequencies is that detecting single-phase faults can be determined using fast Fourier transform (FFT) analysis. The validity of chain equivalent schemas with constant parameters for a single frequency makes it possible to investigate the nature of wave process through the discrete selection of parameters. The proposed method selected several cases of the wave cycles for both voltage and current. Also, during the analysis, several starting times before and after the fault is chosen to determine the total wave distortion. The results show that the best analysis that could detect the faults is three cycles. All the FFT is done using the MATLAB Simulink program.