| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform deterioration diagnosis based on a loss current measuring method using equipment to be used for residual-charge measurement. <P>SOLUTION: An AC voltage is applied between a cable conductor of a cable 3 to be measured and a shield by a testing transformer 1 and cut off at a predetermined phase. The operation is repeated by the number of measurements while changing a cut-off phase to acquire a residual charge amount in each cut-off phase and the residual charge amount is differentiated and converted into a current signal. By analyzing a frequency of the signal, the magnitude (I<SB POS="POST">3</SB>) and phase (θ<SB POS="POST">3</SB>) of a tertiary harmonic component current included in the signal are derived and deterioration diagnosis is performed by a loss current method. Before or after the execution of the deterioration diagnosis, residual charge measurement based on a step charging method is performed to acquire a component corresponding to a voltage of the residual charge signal, deterioration diagnosis is performed, and a deterioration diagnosis result is synthetically derived in combination with the deterioration diagnosis result based on the loss current method. <P>COPYRIGHT: (C)2013,JPO&INPIT |
