| abstract |
The invention discloses a method and a device for live-line testing of ground connection defects of a single-end grounding system of a high-voltage cable, which utilize an alternating current source to apply alternating current stable currents which are different twice and are different in power frequency or field interference frequency to two phases of a three-phase grounding system of the cable through a current limiting device, test the alternating current voltage and current values under injection frequency by using a voltage and current testing device, calculate the resistance and the inductance of each grounding system by using the relation of ohm law, impedance, resistance and inductance and a simultaneous equation, judge the connection defects of the grounding system of the cable when the single-phase resistance of the cable is more than 1 omega and the ratio of any two phases exceeds 2, can live-line detect the electric connection state of a metal sheath of the cable, and have the advantages of simple and convenient operation and high efficiency. |