On-line non-intrusive condition monitoring of high voltage equipment : a review

Continuous monitoring of aging high voltage equipment and early prediction of possible failure modes is becoming an essential and challenging task for many electrical utilities all over the world. There is a growing demand for non-intrusive and non-destructive methods since the electrical utilities prefer to maintain their services undisrupted during these test procedures. There are several already published methodologies available. This paper will review these methods and identify techniques suitable for deriving non-intrusive and non-destructive on-line condition monitoring methods. Emphasis will be given for high voltage power transformers, high voltage power cables and high voltage switchgear.