Investigation of the Propagation of Electrical Trees in a Polymer Matrix in the Corona Condition

Abstract

In a corona environment, the initiation and propagation of electrical trees in a polymer matrix originate from the field enhancement effect. Driven by the macroscopic alternating electric field, a weak alternating current (AC) was passed through the decomposition channel of an electrical tree, and a small amount of alternating electric quantity was present on the tip of the electrical tree, resulting in an enhanced local electric field around the tip of the electrical tree. The emissions of electrons accelerated in the enhanced local electric field resulted in the decomposition of the polymer material, stimulating the propagation of the electrical tree. When inorganic nano-particles with high corona resistibility were introduced into the polymer matrix, the nano-particles were aggregately deposited as the polymer material decomposed. The decomposition channel of the electrical tree was blocked and the current passing through the decomposition channel was shut off, eliminating the enhanced local electric field. As a result, the propagation of electrical trees was restrained and an improved corona resistibility was achieved for the polymer/nano-particles composite material.