| 摘要 |
PURPOSE:To obtain the partial electric discharge measuring method having the sufficiently high detection sensitivity even for the partial electric discharge signal containing the high frequency component over 1MHz and with which the need of the work for demounting a cross bonded wire or grounding wire at an installation site is obviated. CONSTITUTION:A detection impedance 15 is connected at both the edges of the intermediate connection part 12 of an electric power cable 11, and the partial electric discharge of the electric power cable 11 is detected by detecting the electric potential at both the edges of the detection impedance 15. Further, on the outer periphery of a grounding line 16 connected with the intermediate connection part 12 of the electric power cable 11, a core 17 made of a ferrite having manganese.zinc (Mn-Zn) group and nickel.zinc (Ni-Zn) group components having a specific magnetic permeability of 500 or more is installed. Since the ferrite core 17 is installed on the outer periphery of the grounding line 16, the high frequency impedance of the grounding line can be increased, and the detection sensitivity for the partial electric discharge can be improved. |
