Factors Causing Corrosion Damage To Pre-insulated Bushings Caused By Corona

The occurrence of corona discharge is closely related to the site conditions, while dry arc is a phenomenon related to leakage current and only occurs on hydrophilic surfaces (hydrophobic surfaces will not have leakage current). Therefore, for hydrophobic surfaces, corona is the main cause of electrical aging. The factors that may cause pre insulated sleeve corrosion damage caused by corona are as follows:
(1) The charged particles generated by corona discharge impact the surface of the insulating material, causing the main chain of pre insulated junction sleeve to break, and the polymer to depolymerize or partially become low-molecular;
(2) Corona discharge produces active gases such as ozone and nitric acid, and their oxidation and corrosion effects cause insulated joint sleeve to gradually age;
(3) Part of the corona discharge energy is converted into heat energy, and its heat is not easy to dissipate inside the material and gradually accumulates, resulting in a local temperature rise, which can cause thermal cracking of the material;
(4) Corona discharge produces radiation such as ultraviolet rays or X-rays, causing material decomposition.