Application Of Fractal And Chaos Theory On Tracking Test

The growing interest in polymer insulation materials for high voltage applications are mainly due to the simplicity in manufacture, good in-service performance and the low cost of these materials. However, studies show that whenever polymer insulation materials are exposed to an environment that is less than ideal, tracking becomes an imminent possibility. So tracking on the surface of polymer insulation material is consider as a major cause attached importance to the safety and reliability of running electrical equipment.In order to study the characteristic of tracking on the surface and evaluate the insulation ablity of polymer materials, a lot of experiments have been taken to measure the discharge currents. According to the characteristics of statistical self-similarity and complexity of the discharge current, an approach was presented to find the fractal dimension based on the embedding space theory, state space reconstruction and G-P algorithm.This paper makes an investigation of characteristic of suface discharge based on IEC60112. In this reaserch, 3 polymer insulation materials were used, they are PET, EX and PL. The results show that the fractal dimension can be used as an available feature for evaluating the insulation degradation of polymer insulating materials. The higher voltage applied in experiment, the more the fractal dimension is. At last, a comparison was made to point out the different characteristic of the 3 materials.