Simulation of Transformer Magnetic Shield Plate Loss Under Harmonics and DC Bias

In order to study the stray losses of power transformer magnetic shielding plates under harmonics and DC bias magnetism, improved finite element modeling of the TEAM P21 reference family (V.2009) was carried out. Based on the statistical theory of Jiles-Atherton (J-A) hysteresis and Bertotti loss, the magnetic characteristics of monolithic anisotropic silicon steel sheet under the complex working conditions of harmonic and DC bias were analyzed. The harmonic flux density waveform was decomposed into the major magnetic flux and local reversal magnetic flux and the sinusoidal approximation was performed. The calculation model of magnetic loss under harmonic excitation is established, and the transient calculation of stray field and loss under complex excitation was completed. The laminated magnetic shielding plate of 800kV single-phase four-column UHV converter transformer was simulated and calculated, and the distribution and influence of stray loss under harmonic and DC bias magnetism were analyzed, which proved the correctness of the magnetic loss model and provided a reliable basis for the optimal design of transformer magnetic shielding.