A method for locating a fault in a power transmission line with an Intelligent Electronic Device, wherein the IED is connected with one or more measurement equipment connected with the power transmission line, the IED: measuring an arrival time of a first peak, a second peak and a third peak of a travelling wave detected from one or more measurements of electrical parameters of the power transmission line, wherein the one or more measurements are obtained with the one or more measurement equipment; generating two or more initial estimates of the location of the fault, wherein a first initial estimate of the two or more initial estimates is generated based on the arrival time of the first peak, the arrival time of the second peak, and a velocity of propagation of the travelling wave, and a second initial estimate of the two or more initial estimates is generated based on the arrival time of the first peak, the arrival time of the second peak, the velocity of propagation of the travelling wave and length of the power transmission line; estimating of time of initiation of the travelling wave based on one of: the arrival time of the first peak, the first initial estimate and the velocity of propagation of the travelling wave, the arrival time of the second peak, the second initial estimate, and the velocity of propagation of the travelling wave, and the arrival time of the second peak, the second initial estimate, the velocity of propagation of the travelling wave and the length of the power transmission line; estimating an arrival time of the third peak based on one of: the first initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, the second initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, and the second initial estimate, the estimate of time of initiation of the travelling wave, the velocity of propagation of the travelling wave and the length of the power transmission line; and selecting one of the first initial estimate and the second initial estimate as the location of fault, based on a comparison of the estimated arrival time of the third peak with the measured arrival time of the third peak. measuring an arrival time of a first peak, a second peak and a third peak of a travelling wave detected from one or more measurements of electrical parameters of the power transmission line, wherein the one or more measurements are obtained with the one or more measurement equipment; generating two or more initial estimates of the location of the fault, wherein a first initial estimate of the two or more initial estimates is generated based on the arrival time of the first peak, the arrival time of the second peak, and a velocity of propagation of the travelling wave, and a second initial estimate of the two or more initial estimates is generated based on the arrival time of the first peak, the arrival time of the second peak, the velocity of propagation of the travelling wave and length of the power transmission line; estimating of time of initiation of the travelling wave based on one of: the arrival time of the first peak, the first initial estimate and the velocity of propagation of the travelling wave, the arrival time of the second peak, the second initial estimate, and the velocity of propagation of the travelling wave, and the arrival time of the second peak, the second initial estimate, the velocity of propagation of the travelling wave and the length of the power transmission line; the arrival time of the first peak, the first initial estimate and the velocity of propagation of the travelling wave, the arrival time of the second peak, the second initial estimate, and the velocity of propagation of the travelling wave, and the arrival time of the second peak, the second initial estimate, the velocity of propagation of the travelling wave and the length of the power transmission line; estimating an arrival time of the third peak based on one of: the first initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, the second initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, and the second initial estimate, the estimate of time of initiation of the travelling wave, the velocity of propagation of the travelling wave and the length of the power transmission line; and the first initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, the second initial estimate, the estimate of time of initiation of the travelling wave, and the velocity of propagation of the travelling wave, and the second initial estimate, the estimate of time of initiation of the travelling wave, the velocity of propagation of the travelling wave and the length of the power transmission line; and selecting one of the first initial estimate and the second initial estimate as the location of fault, based on a comparison of the estimated arrival time of the third peak with the measured arrival time of the third peak.