Title:
【発明の名称】CVケーブルの絶縁診断方法
Document Type and Number:
Japanese Patent JP2742637
Kind Code:
B2
Abstract:
PURPOSE:To diagnose the degree of deterioration of insulation such as water tree. CONSTITUTION:A power cable 1 to be tested such as a CV cable, which is an object of measurement, has a capacitance Ck between a conductor 1a and a shielding layer 1b. One end of an AC power source S is grounded through an impedance element 2 and the other end is connected onto the conductor 1a side of the power cable 1. The shielding layer 1b of the power cable l and the impedance element 2 are grounded by a common grounding conductor and voltages at the opposite ends of the impedance element 2 are connected to a display unit 6 through a first low-pass filter 3, a resonator 4 and a variable gain amplifier 5. Moreover, a transformer 7, a second low-pass filter 8 and an AC removal circuit 9 are connected to the AC power source S, not mediated by the impedance element 2, and the output of the AC removal circuit 9 is connected to a gain control input end of the variable gain amplifier 5. On the occasion of measurement, an output of the amplifier 5 becomes large in accordance with level of water tree.
Inventors:
Shigeki Yoshida
Kakuda Miki
Takao Sanada
Akihiro Fukumoto
Kakuda Miki
Takao Sanada
Akihiro Fukumoto
Application Number:
JP32683891A
Publication Date:
April 22, 1998
Filing Date:
November 15, 1991
Export Citation:
Assignee:
THE TOKYO ELECTRIC POWER COMPANY,INCORPORATED
Mitsubishi Cable Industries, Ltd.
Mitsubishi Cable Industries, Ltd.
International Classes:
G01R31/02; G01R31/12; (IPC1-7): G01R31/12; G01R31/02
Domestic Patent References:
| JP6435281A | ||||
| JP331776A |
Attorney, Agent or Firm:
Hibiya Masahiko