The use of ultrasound for the detection of water trees in XLPE cable

摘要

The results show that this technique could be used to aid the location of water trees. Although not perfect, the 95% success rate is sufficiently high to give a good idea as to the density of trees in a given cable. The network could only be trained and tested with trees that could be visually seen through the translucent polyethylene. The technique should not however be impaired by an external screen or other opaque barrier so long as the acoustic energy has a good path through the insulation. Other work on power cables has shown that only metal armouring provides an impenetrable barrier to ultrasound.