Investigation on Online Fault Location Techniques During Factory Testing on Manufactured Cable Lengths

The operational constraints for the supply and exercise of HV extruded cable systems requires a fast and reliable localization of possible faults in cable insulation. Methods are available in the literature for offline fault location for both underground and (long) submarine cables installed in the field. The main method used is Time Domain Reflectometry (TDR), which works well when the fault impedance is low, but other methods are also available for relatively high fault impedances. However, such methods require a subsequent fault pin-pointing that works well offline and in the field. On the other side, there is the need of an effective and extremely-accurate localization method that can be applied on factory tests as well as on site. The purpose of this work is to get insights on such effective online fault localization technique in factory-tested cables, based on the analysis of the fault curve and on its comparison to different offline fault localization methods.