Transformer Excitation Characteristics Research under DC Bias

Solar storms and power engineering HVDC, make the earth there geomagnetic induced current and direct current. If the DC current into the neutral grounding transformer, the transformer will be caused bias magnetic phenomena, changing its excitation characteristics, interfere with the normal operation of power systems and equipment. This paper considers the impact on the excitation characteristics of hysteresis effects, establishing excitation characteristics calculation model, proposes an improved graphics corresponding method to calculate and analyze the open circuit excitation characteristics of single-phase transformer in three columns under DC bias, the experimental results prove the validity of the proposed method.