Simulation analysis of spatial electromagnetic field of transformer core considering nonlinear B-H curve

Transformer core excitation characteristics are directly related to transformer operating conditions and life losses, and different core characteristics produce different spatial electromagnetic field distributions. In this paper, this paper construct a single-phase E-shaped transformer core model considering the nonlinear B-H curve, based on the principle of field-circuit coupling, and apply an external excitation source to investigate the trend of spatial electromagnetic field distribution and the distribution law of heat loss under nonlinear conditions. The simulation results show that when the core is saturated, the spatial electromagnetic field changes to nonlinear characteristics, at which time the spatial electromagnetic field is concentrated in the center column of the transformer, and the loss in the center column is too large; secondly, the loss in the upper and lower ends of the core is low, and the loss reaches the maximum at the corner of the center of the core. At the same time, the transformer current distortion occurs, the loss will increase sharply, and there is a rapid reduction in output current.