| 摘要 |
PROBLEM TO BE SOLVED: To precisely measure a direct current of an insulation deterioration signal in a power cable, under a hot-line condition. SOLUTION: In this deterioration determining device for the power cable, a deteriorated condition of the power cable is determined, based on a direct current value calculated by subtracting a stray current from a current value comprising a sum of the direct current and the stray current, in a measuring circuit for measuring a grounding current in one side of the power cable under the hot-line condition. The deterioration determining device has the first current calculation part for calculating the summed current value based on the grounding current, a commercial wave attenuation part for attenuating to a prescribed level a sine wave current for commercial wave having an asymmetric distortion component containing a direct current component based on the grounding current, while keeping a level of the distortion component, and the second current calculating part for calculating a stray current value based on the sine wave current output from the commercial wave attenuation part. COPYRIGHT: (C)2004,JPO
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