Single Line Fault Location of Parallel Double Transmission Line on Same Tower Based on Two-Terminal Electrical Quantities

To solve the problem of single line fault of parallel double transmission line on the same tower, by means of considering the influence of zero-sequence mutual inductance of parallel double transmission line a fault location algorithm based on two-terminal electrical quantities of the faulty line is proposed. According to the equivalent sequential network of faulty single line, the single line fault location equation is derived by use of the boundary condition of faulty line voltage under single line failure mode. In the proposed algorithm, the terminal voltage and two terminal power frequency currents offered by existing segregated phase current differential protection is adopted, so the principle of the proposed algorithm is independent of transition resistance and system impedance. The fault location of various types of faults occurred at different positions of single line under the condition of different transition resistances, system impedances and loads is simulated by PSCAD/EMTDC. Simulation results show that by use of the proposed algorithm the single line fault location of parallel double transmission line on the same tower is accurate, and it is also proved that the proposed algorithm is independent of transition resistance, system impedance and load situation.