An accurate fault location method for multi-circuit series compensated transmission lines

This paper presents a fault location method for multi-circuit series compensated line using phasor data from intelligent electronic devices (IEDs) available at both ends. In case of unavailability of synchronized data, analytical synchronization is obtained using an operator. In the formulation, the method considers untransposed line sections resulting on two sides of the fault and the distributed nature of line. For a healthy phase, currents on two sides at the fault point are equal unlike different currents on two sides in a faulted phase. This is checked over the line length and the fault location is pinpointed. The method does not require the model of the series compensation placed at any location on the line and can be used for both inter and intra-circuit faults. It also considers reactive component of the fault impedance for accurate fault location. The method is tested using PSCAD/EMTDC simulations for a multi-circuit series-compensated line in Indian power grid. Evaluation study confirms the validity of the method for various faults.