FEA Simulation of the Electromagnetic Effects on the Flux Distribution of the Joints in the Transformer Core Structure

In the manufacturing of the transformer the occurrence of air gaps at the joints of the legs and yokes of the core lamination stacking of the transformers is inevitable. The air-gap in the core joints affects the magnetic flux density and the magnetic flux distribution in the core. The location, shape, length and number of air-gaps all are different from each other. The increase in air-gap of transformer core will increase the reluctance of the core causing a reduction in the total magnetic flux value. The effects of the air-gap in joints cannot be exactly analyzed mathematically. However, the electromagnetic modeling using the finite element method provides facility to simulate and analyze such a problem. In this study, the effects of air-gaps with different shapes and length in the transformer legs on the stray magnetic are compared with using Finite Element Analysis (FEA) software.