DISTANCE PROTECTION METHOD FOR HALF-WAVELENGTH LINES AND USE THEREOF

摘要

The present invention relates to a distance protection method for half-wavelength lines. Said method uses correction algorithms to calculate apparent impedances in order to generate distance protection zones correctly, as the conventional distance protection is not suitable for protecting a very long transmission line (1000-3000 km), since it covers only the initial line section and the relay-calculated apparent impedances do not correspond to linear curves for faults along the line. In addition, the method uses three-phase quadrupoles to detect faults in the middle of the line and to identify whether the fault is inside or outside the line.