| 摘要 |
The diagnosis method of deterioration of electric power cable is that which diagnoses the deterioration accurately without a especial effort to reduce the harmonics in an electric power source equipment for test. Loss current component, which is obtained by rejecting the capacitive component of frequency f1 contained in the total current flowing in the insulation of the electric power cable, when superimposing a first voltage V1 of frequency f1 and a second voltage V2 of frequency f2 (V1 ≥ V2) to an electric power cable, is measured. Further the current components and the frequency components contained in the current is investigated. The deterioration diagnosis is implemented by frequency components excepting the frequency f1, f2 and the their harmonic. As combinations of frequency f1 and f2 of the AC voltage a combination that frequency f2 is two times of the frequency f1 is used, and the current components of frequency components of four times of the first voltage in the frequency components are measured, and the deterioration are diagnosed by the current components and the superimposed phases &thetas;4. <IMAGE> |
