Transmission lines fault location using transient signal spectrum

This paper proposes a method for fault location on transmission lines, which is based on time to frequency domain transformation of transient signals of the fault instant measured at one end. Fast Fourier Transform (FFT) is used for time to frequency domain transformation and frequency of the first fault generated harmonic is utilised for determination of the fault location using the travelling wave theory of the transmission line. The accuracy of the method has been tested using the simulations carried out in Alternative Transients Program (ATP/EMTP) with frequency-dependent distributed parameter transmission line model by considering several cases and various types of faults, different values of fault resistance and phase angle at fault instant. The method has good accuracy and the simulation results show that the accuracy of the method is insensitive to the fault resistance and phase angle of the fault instant. Reactive elements may affect the resolution but, it can be removed by applying the correction procedure proposed.