Performance of biologically contaminated high voltage insulators

Biological growth has been observed on insulators installed all over the world. However, so far, its impact on insulator performance is not well known. This paper summarizes the work published in the field. Based on the gathered experiences, it can be concluded that microbiological growth is unlikely to cause severe degradation of the rubber housings of non-ceramic insulators. Furthermore, it seems that the impact of growth on the insulator performance is rather low. Techniques available for detection and characterisation of growth on insulators are also described and discusses. Among those, laser-induced fluorescence (LIF) spectroscopy has been found to give good results in remote detection of micro-organisms.