Ultra-high speed protection of series compensated lines

An ultra-high-speed (UHS) protective algorithm based on traveling waves was developed and applied to the protection of series compensated lines. The basic principles of the algorithm are described and its response to protective gap flashover is studied for a range of fault conditions. Results of simulations confirm the efficacy and the excellent discriminating features of the algorithm. The nonuniformities introduced by the presence of compensating capacitors can be accounted for in the discriminating features of the algorithm. The impedance of the capacitors is negligible for the incremental components used by the UHS algorithm. Protective gap flashover, which normally causes difficulties with conventional schemes, does not normally occur within the time interval analyzed by the algorithm. In the unlikely event of a flashover occurring discrimination is still maintained. These features make the UHS algorithm particularly suitable for application to series compensated lines.>