| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly sensitive partial discharge measurement method without being affected by the noise of aerial corona discharge or the like. SOLUTION: Foil electrodes 7 are attached to both sides of an insulating cylinder 5 of an air terminal connection part 6, a detection impedance element 8 is connected to the foil electrodes 7, and the voltage across both its ends is inputted to a noise filter 13. A foil electrode 11 for measuring a voltage to the ground is attached to the air terminal side of the insulating cylinder 5, and a noise signal is detected from the voltage to the ground of the foil electrode 11, and inputted to the noise filter 13. The noise filter 13 removes the noise from the measurement signal generated in the detection impedance element 8 by using the noise signal. The measurement signal with the noise removed is inputted to a partial discharge measuring instrument 9, and the partial discharge is measured. The noise may be detected by mounting cores having high permeability to cables on both side of an intermediate connection part in the vicinity of the terminal connection part 6, and by detecting a potential difference between the foil electrodes mounted to both the ends thereof. |
