Adaptive fast protection technique for uncompensated/compensated double-circuit transmission lines connected to large-scale wind farms

摘要

The penetration of large-scale offshore wind farms in power grids has a negative effect on the operation of the conventional distance relays. In this study, a new protection technique is presented for uncompensated/compensated double-circuit transmission lines utilising one-end current measurements. The proposed protection technique does not require any information regarding the transmission line parameters, wind farms, or the compensation devices. In addition, the errors in phasor estimation due to the generated sub-harmonics and inter-harmonics by the wind generators are avoided as the current samples are directly used. Comprehensive studies are implemented on PSCAD/EMTDC software considering numerous cases of external and internal faults. In addition, the double-circuit transmission line is modelled using the frequency-dependent phase model and the mutual-coupling between both circuits are considered. The recorded results confirm the high efficacy of the proposed protection technique with respect to fault type, fault location, and fault resistance.