Long-term reliability of amorphous alloy wound core distribution transformers

Abstract

In order to verify lonn-term reliability of amorphous alloy wound core distribution transformers, accelerated aging tests and field trials used by actual transformers were practiced. ,As for accelerated aging tests, short-circuit tests were added to imitate mechanical stress in operation on a utility's distribution system. of 30 years, which was the normal expected transformer's life, magnetic characteristic was unchanged, so these transformers could be operated.Also, about field trials, two hundred transformers of four kinds were installed on a utility's distribution system to look into no-load characteristics. They were equipped with a mechanism to measure load current, background vibration and lightning surge current, so the influence for magnetic characteristic could be inspected.As a result, remarkable change wasn' t seen even after six months.As a result, even after the equivalent