Electrical Treeing Phenomenon

Summary

An electrical tree is a type of electrical aging and degradation phenomenon of insulating materials; once it crosses the insulation, electrical breakdown occurs, thereby affecting the operation safety of polymeric cables. This chapter focuses on the electrical treeing initiation and breakdown phenomenon of polypropylene (PP) cable insulation under DC and impulse combined voltages. High‐voltage cables require good mechanical properties to withstand various extreme installation environments, such as high drop terrains and the laying process of submarine cables through towing pipes. The occurrence of large bending deformations in cables, due to reduced turning radius, can lead to the concentration of mechanical stress and the development of microcracks. The chapter focuses on the electrical treeing characteristics of PP and cross‐linked polyethylene insulation under low‐temperature environment. Accumulated damage of breakdown electrical tree refers to the number of pixels in the area covered by breakdown electrical tree, which is used to characterize the damage area of the insulation material.