Fault location method for partial coupling four-circuit overhead lines with different voltages

Few research articles discussed the issue of fault location for partial coupling four-circuit overhead lines with different voltages. In this work, a fault location method is proposed for partial coupling untransposed four-circuit overhead line with different voltages on the same tower using synchronized current data. The distributed-parameter model of the line and the mutual couplings between all circuits are considered. The faulty circuits are initially recognized, and the deduced analytical equation for fault location does not depend on fault type or fault resistance. In addition, the locations of normal-shunt faults, cross-circuit faults and cross-voltage faults between different voltage levels are estimated precisely. Emulation studies are conducted by DIgSILENT Power Factory and MATLAB software to validate the proposed method under various fault resistances, fault locations and fault inception angles. In addition, the effect of estimation errors in line parameters as well as measurement and synchronization errors is tested.