Analytical results of harmonic influenced electrical tree growth images

Electrical treeing is a common cause of polymeric insulation failure. Visually oriented research into this ageing mechanism has been limited exclusively to laboratory based exercises. Employing relatively high speed and high resolution cameras have advanced the acquisition of progressive, two dimensional digital colour electrical tree growth images. This paper presents an analysis of processed harmonic influenced electrical tree growth images from a series of laboratory based experiments. The electrical tree growth, quantified using the area, fractal dimension, width length ratio, intensity frequency index, perimeter and estimated volume methods was investigated for a correlation to power quality. The results confirmed total harmonic distortion, waveshape factor and harmonic order were influential factors on electrical tree growth.