A novel single-ended fault location method for locating double-phase to earth faults

To accurately locate the fault position on the EHV transmission line, the impact of distributed capacitance cannot be ignored. A novel fault location method for locating double-phase to earth faults occurred on the transmission line is presented based on the distributed parameter model of the transmission line. In this method, only the voltage and current of single end are used. The residual phase voltage at the fault point should have the same phase angle as the current through fault branch due to the pure resistive characteristics of the fault path impedance. By virtue of searching the minimum phase angle difference between the phase voltage along the transmission line and the fault-component current measured by the protection, the fault distance can be located. It should be pointed out that the algorithm is based on power-frequency voltages and currents. Therefore, it can be implemented in the existing protection devices easily. EMTDC based simulation model is used to generate the data to verify the proposed fault location algorithm. The test results are satisfactory in terms of engineering applications.