PURPOSE: To measure the partial discharge generating position of a cable without generating a measuring error, by determining direct wave arrival time difference by a measuring cable and an auxiliary cable connected to said cable at the other terminal through a coupling condenser and having the same standard and length as said cable.
CONSTITUTION: The other terminal of a main cable 1 equipped with a joint 8, across which impedance changes, is connected to an auxiliary cable 9 having the same standard and length as the main cable 1 through a coupling condenser 10. When high voltage is applied to the core wire 1a and the insulator 1b of the cable 1 from one terminal thereof, partial discharge is generated at the dielectric breakdown point A between said one terminal and the joint 8 and the high voltage pulse reflected from the point A directly reaches to said one terminal at first and detected through a condenser 4, a detection impedance 5 and an amplifier 6 and memory 14 is triggered. In addition, the direct wave corresponding to the reflective wave from the other terminal of the cable 1 through the cable 9 is detected through an amplifier 13 and stored in the memory 14 and the measurement of a partial discharge position without a measuring error is performed on the basis of the detection time interval of both direct waves without exerting influence upon the reflective wave from the joint 8.
SASAKI NOBUHIRO
AIHARA MITSUGI
EBINUMA YASUMITSU
ENDOU YOSHIKATSU
MUNAKATA ICHIROU
TOKYO DENSETSU SERVICE KK
| JPS5616878A | 1981-02-18 |