Comparison between the localized power loss and flux distribution in a three phase distribution transformer 100 kva assembled from various type of T-joint geometry with Staggered Yoke

Abstract

This paper describes the result of an investigation of the variation of localized power loss and flux distribution in 3-phase transformer cores 100kVA assembled from various types of T-joint geometry. The localized power loss has been measured using iron loss tester in the model of setting of core built from M5 (CRGO) grades material of laminations and here the flux distribution has been calculated using computational method. The localized power loss is less at the outer edge of the T-joint. The localized power loss is higher at the inner edge of the T-joint. The localized power loss of the transformer core assembled with 60° T-joint of core laminations are 29.3% , 24.2% and 13% better than the transformer cores assembled with 90° T-joint, 23° T-joint and 45° T-joint of core laminations respectively at 1.5T, 50 Hz. The result of this investigation shows that the localized power loss at the transformer core assembled with the 60° T-joint is less than the other types. The flux lines show that the flux penetration into the centre limb of transformer core is an important factor in causing the difference in performance of transformer core.