Research on Electromagnetic Characteristics of Single-Phase Transformer under DC Bias

In order to study the influence of DC bias on the electromagnetic characteristics of the transformer, firstly, the equivalent circuit model of the single-phase transformer is established according to the mechanism of DC bias. Secondly, the model is simulated by using the MATLAB software. Finally, the results show that the DC bias makes the hysteresis loop, magnetostrictive curve and excitation current waveform lose their original symmetry, indicating that a distortion phenomenon occurs, and the peak values of excitation current, magnetic flux density and deformation increase significantly, which shows that the loss of the transformer increases and the vibration intensifies. As the DC current increases, the degree of this distortion will be further exacerbated. In addition, the magnetostrictive curve also has saturation characteristics and hysteresis characteristics.