Patent ID: 6654220
Filing Date: 2003-11-25
Classification: H02H

Abstract:
A method for protection of an electrical power line, particularly in the event of short circuits, in which an adaptive estimator is used to determine impedance values (Zi) from measurement points (ik, uk) in measurement windows, with each measurement window containing a number of measurement points, and with the line being switched off if the impedance values (Z) satisfy an unacceptability criterion (s) wherein a warning signal (W) is produced only if a radio-frequency signal above a predetermined threshold value is detected on the line, and in that, when the warning signal (W) occurs, the respective measurement window is located such that its start essentially coincides with the occurence of the warning signal (W) and/or in that, when the warning signal (W) occurs, the respective measurement window is shortened in comparison to normal operation.