| 摘要 |
PCT No. PCT/CH86/00066 Sec. 371 Date Jan. 16, 1987 Sec. 102(e) Date Jan. 16, 1987 PCT Filed May 20, 1986 PCT Pub. No. WO86/07160 PCT Pub. Date Dec. 4, 1986.The control apparatus has an antenna (10) for the reception of electromagnetic radiation emitted from the alternating current transmission line. The antenna (10) is connected to an amplifying device (20) the signal output (22) of which is connected to an oscilloscope (30) in such a manner that the output signals of the amplifying device (20) effect both vertical and horizontal deflection of the image spot on the image screen of the oscilloscope (30). The amplifying device (20) is constructed for the amplification of a broad frequency range extending from below the line frequency to at least 20 kHz, wherein the amplification in the frequency range below about 10 kHz is reduced. The whole frequency spectrum of the output signals of the amplifier device (20) is fed to the oscilloscope (30). In the course of monitoring a transmission line the low frequency signal from the alternating line voltage appears on the image screen of the oscilloscope (30) as a smooth closed curve, while in contrast the high frequency signals originating from corona discharges at the fault locations of the transmission line appear as disturbances of the smooth closed curve. The shape of the disturbances, their position on the closed curve and their amplitudes enable the type and condition of fault locations to be determined. |
