| 摘要 |
A converter station (1) in a high voltage direct current power transmission is provided with an electrode line protective device for detection of ground faults on the electrode line (7) of the station. An alternating voltage generator (19) injects an alternating signal with a predetermined frequency in the electrode line. The two ends of the electrode line are provided with suppression filters (9, 10) tuned to the measuring frequency. The suppression filter (10) arranged at the remote end of the electrode line, in relation to the feeding point, is matched, by means of a resistor (14), to the wave impedance of the electrode line. An impedance measuring device (21) senses the impedance of the electrode line at the feeding point in relation to ground at the measuring frequency. An indicating signal (f) is delivered from the measuring device if the impedance measured deviates from the impedance of the electrode line when in a faultless state. |
