Water treeing and condition assessment of high voltage XLPE cables

The results show that the degree of water treeing in HV XLPE cables (36 kV and above) is strongly dependent upon the cable design and the service (system) voltage. The water trees are typically relatively short, but their density is similar to that observed in medium voltage cables with similar design. The results from the nondestructive diagnostic testing show that it can be possible to detect water treeing also in old high voltage cables extending diagnostic techniques developed for medium voltage cables.