Abstract

The high voltage side of distribution transformers is usually protected against lightning surges by lightning arresters. In installation of lightning arresters, the separation distance between the lightning arrester and the high voltage bushing of transformer is importance factor. The new method for determination reasonable installation location of the lightning arrester, accounting technical - economic criteria and several influential factors such as the ground flash density, shielding factor, failure rate, lifetime of a transformer and earth resistance is presented in this paper. The installation of lighting arrester in 400kVA, 22/0.4kV distribution station in Ho Chi Minh City is also discussed and offered practical recommendations.