Partial discharge patterns in conducting and non-conducting electrical trees

Abstract

Abstract-Previous observations on electrical tree growth in epoxy resins has shown that different types of tree growth structure, electrically conducting and non-conducting, can occur dependent on the state, glassy or flexible, of the epoxy resin. In this current study, the partial discharge characteristics were characterized experimentally at a temperature of 20C within two different epoxy resins systems having glass transition temperatures of 0C and 50C. The partial discharge activity (determined from apparent charge measurements) was characterized in terms of ~q~n patterns using statistical tools. The aim was to compare the apparent charge measurements obtained from conducting and non-conducting electrical tree structures with computer simulations of the partial discharge activity in both conducting and non-conducting electrical trees. The results show that there is a significant relationship between the local extent of the partial discharge phenomena, as determined by the conductivity of the tree channels, and the apparent charge, as shown by the experimental and simulated partial discharge patterns. The implications of this work for partial discharge detection as well as for condition monitoring in real insulating systems are discussed.

Electrical treeing in a glassy epoxy resin — The filamentary tree and the PD tree

“…Electrical trees can be further referred to as branch, bush or bush-branch trees, based on their morphology and visual similarity to their botanical namesakes. They are also characterized as electrically conducting or non-conducting artifacts based on their conductivity relative to the dielectric [2]. However, the radii of constituent tree channels are rarely used to classify trees.…”

Prognostic modeling for electrical treeing in solid insulation using pulse sequence analysis

“…These can lead to a reduction in life, which in turn can lower the reliability of electrical power systems. Therefore, a lot of research effort, activities and publications are directed towards a better understanding of degradation phenomena [1] [2], the creation of tools for insulation diagnosis [3] [4] and the establishment of remaining life estimation techniques [5] [6].…”

The Applications of Current Comparators in the Measurements on High Voltage Insulation

“…In the application on PD measurement, the detection winding must be connected directly to an oscilloscope or partial discharge detector [7]. The reason why the detection winding must be connected directly to the oscilloscope is that the filter used for harmonic measurement is a low-pass filter with a cut-off frequency of l000Hz.…”