For access to this article, please select a purchase option:
IET members benefit from discounts to all IET publications and free access to E&T Magazine. If you are an IET member, log in to your account and the discounts will automatically be applied.
Your recommendation has been sent to your librarian.
Under long-term environmental impact of electromechanical load, pollution, ambient temperature and humidity, the micropore and crack in cap and pin of porcelain Insulators will gradually expand, the mechanical strength and insulation performance deteriorate. When subjected to lightning stroke or pollution flashover, it is likely to cause vicious accidents such as explosion or insulator string fracture. In this paper, lightning stroke-caused fault of 500 kV line porcelain insulators is analyzed, combined with lightning positioning system, line distributed fault location system and insulators' test. It can conclude that a number of low (zero) resistance insulators in the string exist before lightning flashover, when the shielding failure lightning strike C phase and causing the insulator string flashover, most of the power frequency freewheeling energy is discharged from the low (zero) value insulator in the porcelain discharge channel, and the heat generated causes the insulator to explode, causing string fracture. It is recommended to check the low (zero) value insulators in the line, adopting leading-type lightening protection measures such as installing line surge arrester or coupling ground wire in heavy lightening area.
Inspec keywords: fracture; flashover; porcelain insulators; cable shielding; power transmission faults; power overhead lines; arresters; environmental factors; insulator contamination; lightning protection; electromagnetic shielding; power transmission protection; cracks; fault location
Subjects: Dielectric breakdown and discharges; Power line supports, insulators and connectors; Protection apparatus; Electromagnetic compatibility and interference; Overhead power lines; Environmental factors