engleski

The 3D magnetic field calculation of a dry-type transformer by integral equations

The 3D magnetic field calculation of a dry-type transformer was performed for quasistatic case by using integral equations. Windings and LV terminals are primary sources of the magnetic field. The core of the transformer was modeled using a secondary source K – line current density on the surface of the core. Since the core is laminated, it was assumed to have no eddy currents. All other ferromagnetic parts of the transformer were ignored. The surface of the core was divided into N rectangular elements. The secondary source K was assumed to be constant all over the elementary surface. In order to find K, the system of integral equations was transformed into linear system. The matrix coefficients were evaluated from surface integrals. Given that rectangle was chosen as the elementary surface, integration limits are constant and integrals are soluble analytically. The size of the system matrix is 2N x 2N. We compared our calculations with measurements for magnetic induction.

magnetic field; transformer; integral equations

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