Influence of the Mix 60-23 in different layers of T-joint of 3Phase Transformer Core on Longitudinal Direction of Flux Distribution

Abstract

This paper describes the result of investigation of longitudinal direction of flux distribution in 100kVA 3phase distribution transformer assembled with the mix 60-23 in different layers of T-joint. The measurement involves the fundamental and third harmonic of the easy and ha r d direction of flux density at each location measurement. The flux distributions have been measured using no load test by arrays of search coil in MS (CGO) grades material of transformer core laminations. The localised flux density at the outer the mix 60- 23 in different layers of T-joint is 1.4T and rises to be 1. 7T at the inner edges of the mix 60 - 23 in different layers of T-joint when the transformer core energized 1.5 T 50Hz. Harmonic occurs mostly in the T-joint where local regions are saturated and the flux deviates from the rolling direction. A small amount of flux deviation from the rolling direction occurs at the overlap, but no rotational flux is present in the joint. This paper describes the result of measurement of normal flux distribution 3-phase 100kVA transformer core assembled with the mix 60-23 in different layers of T-joint. The investigation involves the variation of normal flux distribution in the core lamination. The normal flux distribution has been measured using no load test by arrays of search coil. The highest normal flux distribution occurs at the corner edge of the centre limb that is 0.17T and lowest at upper edge of yoke that is 0.09T. The average value of normal flux distribution is high at flux transfer region of the lamination. The flux transfer mechanism shows that two separate path flowing horizontally In the yoke before leaving the lamination to vertically adjacent layer and combine with the llux In that layer. Then, It will transfer back to origin region and extend through the center limb.