Losses calculation in transformer tie plate using the finite element method

The 3D leakage magnetic field in a transformer is calculated by using the surface impedance method based on two scalar magnetic potentials. The leakage magnetic flux density and the highest temperature rise of the tie plate calculated are compared with the measured values, and the results are satisfied for engineering design. The nonlinear eddy current field inside the tie plate is calculated by using H as the state variable directly. The eddy current and hysteresis losses of the tie plate are calculated respectively. The influences are analyzed of the width and the slot number of the tie plate and the transformer load current.