Abstract-- Phasor Measurement Units (PMUs) have gained a great popularity in the field of control and wide area protection during the last decade. One of the major protection applications based on PMUs technology is to determine the fault location in a transmission line. Therefore, several researches have been developed in the field of fault location. Some of the researches are based on one-end measurements. But, a greater accuracy has been achieved on the basis of two-end measurements. Many researchers suggested only voltage measurements to avoid the current transformers (CT) errors. While, others suggested methods depend on both voltages and current measurements with a higher accuracy CTs. A few researches have been developed in fault location of series compensated line. This paper introduces a generalized model of fault location algorithm for both uncompensated and series compensated transmission line. The proposed algorithm is based on the distributed parameters of the transmission line in the determination of fault location. Moreover, the proposed algorithm utilizes the synchronized measurements of voltages and currents at both ends of the line. The proposed algorithm is general for any allocation of series compensation elements. The proposed algorithm is tested through the PSCAD offline simulation program and the mathematical analysis with the aid MATLAB. I. INTRODUCTION ault location has been studied for a long time and varieties of fault location algorithms have been developed so far. The majority of them are based on an impedance principle, making use of the fundamental frequency voltages and currents [1]. Depending on the availability of the fault locator input signal, they can be categorized as one-end algorithms, two-end algorithms. The One-end impedance- based fault-location algorithms estimate a distance to fault with use of voltages and currents acquired at a particular end of the line. Eriksson et al [2] describe a microprocessor based fault locator, which uses novel compensation techniques to improve accuracy. Jonas et al [3] present a technique for single-ended location of resistive earth faults on power transmission lines. Djuric et al [4] suggest an algorithm for fault location which uses data from one end of transmission line. Adu [5] describe a fault locating system that has been developed at Mehta Tech, Inc (USA). Izykowski at al [6] present a method for fault location in parallel transmission lines with the availability of complete measurements from one end of the lines. Pereira at el [7] introduce a new algorithm for fault location in transmission lines using the calculation of fault distance phasors of voltage and current at one of the line terminals through an optimization process. Eisa and Ramar presented two researches to get an accurate on end fault location for overhead transmission lines [8, 9]. The fault location method is embedded in a general n-bus interconnected power system. Two-end algorithms process signals from both terminals of the line and thus a larger amount of information is utilized. Therefore, the performance of the two end algorithms is generally superior in comparison to the one-end approaches. Some methods are free of CTs to eliminate their error; Galijasevic et al [10] present a novel method for locating short circuit faults in electric power systems. In cases where impedance model is available, Brahma, et al [11] describe a fault location method for transmission lines using only synchronized voltage measurements at both ends of the line, eliminating the inherent error due to CT. Fairouzjah, et al [12] present a method based on the synchronized voltage measurements technique in order to identify the fault locations in two and three terminal transmission lines using Thevenin model of faulted system and transforms the whole parameters to symmetric components. Several researches used both voltages and currents at both ends in the fault location problem. Jiang et al [13, 14] propose an adaptive fault detection/location technique based on PMU for an EHV/UHV transmission line. Pereira et al [15] introduce a research deals with fault location calculations that use voltages and currents during transient conditions and pre fault values. The authors stated that the main contribution is the possibility of fault location even with the lack of some current measurements as in the case of current transformers saturation or even when data acquisition process fails. Wang et al [16] propose fault location formulas using synchronized sequence measurements. Abdelaziz, et al [17] introduce a new approach depends on the both voltage and current measurements at the two terminals of the transmission line with the help of distributed parameters of the uncompensated transmission line. Few researches have studied the fault location for series compensated transmission lines. Yu et al [18] present a fault location algorithm based on PMUs for series compensated lines. The authors claim that the proposed technique in the research can be easily applied to any series FACTS compensated line. Section II of this paper introduces the proposed mathematical algorithm for both uncompensated and series compensated transmission line with different allocations of series compensation element. Section III presents the simulation results of the series compensation element testing. Section IV shows the simulation results of fault location for an uncompensated line. Section V introduces how the proposed Phasor Measurement Units (PMUs) Based Fault Location of Series Compensated Transmission Lines A. Y. Abdelaziz, S. F. Mekhamer, and M. Ezzat Department of Electric Power and Machines Engineering Ain Shams University, Cairo, Egypt F