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Abstract: This paper presents a new design of transformer shape core with used in railway system via analyzed the magnetic vector potential in the form of partial differential equation. Finite element method is used to simulate three-dimensional system. This paper focuses on the magnetic vector potential behavior on core transformer with V-connection, while the transformer was supplied voltage from three phase system. The unbalance input voltage is divided to three case studies in this paper: C-A couple phase, A-B couple phase and B-C couple phase from three-phase system. In addition, a design of transformer shape core occurred on the corner that is the intersection between vertical core and horizontal core with 5mm radius curves. The simulation results compare magnetic vector potential between the original shape of transformer core and the new design of transformer core even though the supplied voltage are unbalanced. Nevertheless, the results shown that the new design of transformer core is more highly uniform a magnetic vector potential distribution in the transformer core and suitable for guideline for improving the shape of transformer core to reduce the core loss.

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