Contribution factors to transformer failure under no load condition and mitigation action

Abstract

The study on transformer failure was carried out on commercial 1500 kVA 33/11 kV in TNB network distribution systems. The damage experienced by the transformer under study was suspected due to the transient surge overvoltage phenomenon activities. The source of surge has been investigated and analyzed from the recorded lighting data captured from the substation circuit. This paper presents the holistic approach of possible causes on the surge transient. Internal and external overvoltage sources are mentioned in detail to described the failure incident. Recommendation to prevent such failure in the future and to improve transformer performance are also discussed.