An accurate fault location algorithm based on parameter identification of linear differential equation using one terminal data

In this paper, an accurate single-ended fault location algorithm using linear differential equations is introduced. Based on the R-L model of transmission lines, this algorithm is inferred from the differential equations of fault network and fault components network. The fault location linear differential equation takes the fault distance, fault resistance and source impedance (a resistance and an inductance here) of system after fault point as unknown variables. Seek these four unknown variables from the solution of coefficients of the fault location equation. This method does not need iteration and initial value and is helpful in distance relay because of the uniqueness of its solution. Simulation results prove the high accuracy and low computational costs of this algorithm. Variations of source impedance and fluctuations in power frequency have no effect in fault location result. The algorithm is suitable in all fault types.