Abstract: Current and voltage values (uk, ik) are measured for protection of an electrical power line (1). An adaptive estimator is used to analyze all the values within a measurement window, and to convert them to impedance values (Z). The line (1) is switched off if the impedance values (Z) assume unacceptable values. In order to shorten the reaction time, a warning signal (W) is produced if powerful radio-frequency signals are detected on the line (1). When the warning signal (W) occurs, the respective measurement window is located such that its start matches the time of the warning signal (W), and/or the respective measurement window is shortened.

Abstract: Current and voltage values (uk, ik) are measured for protection of an electrical power line (1). An adaptive estimator is used to analyze all the values within a measurement window, and to convert them to impedance values (Z). The line (1) is switched off if the impedance values (Z) assume unacceptable values. In order to shorten the reaction time, a warning signal (W) is produced if powerful radio-frequency signals are detected on the line (1). When the warning signal (W) occurs, the respective measurement window is located such that its start matches the time of the warning signal (W), and/or the respective measurement window is shortened.

Abstract: This high-voltage installation has a metallic enclosure (1) which is filled with insulating gas and surrounds voltage-carrying active parts. In addition, it has at least one at least partial protective coating (7, 9, 10) either on the internal surface of the enclosure (1) or on the external surface over the active parts, or at least one at least partial protective coating (7, 9, 10) both on the internal surface of the enclosure (1) and on the external surface of the active parts.It is intended to provide a high-voltage installation in which free electrons are also reliably removed from the insulating gaps and in which partial discharges generated by free particles are reduced to noncritical values of intensity. This is achieved in that the at least one protective coating (7, 9, 10) is doped with at least one fullerene which absorbs free electrons. Protective coatings which have a surface of vapor-deposited fullerene are also particularly suitable.