A statistical method for stastical appraisal of the power cable conditions based on the TD and PD diagsnostics result

Abstract

This study handles one of the key questions of network operators: How can the remaining life time of underground power cables be estimated? The answer to this question is explained by a new method of KEPCO Korea. When combining VLF Tan Delta (TD) and Partial Discharge (PD) diagnostic it is possible to identify and localize weak individual spots along a cable. After weak spots are cleared, the general aging condition of the cable can be evaluated and the Remaining Life Time can be estimated. The implementation of this approach in the KEPCO Distribution Networks is illustrated in a practical case study. A new tool for asset managers is available and it is expected that it will help to further develop the preventive maintenance approach by power utilities all around the world.