Calculation of Temperature Rise of the High-voltage Winding in the Power Transformer under DC Magnetic Biasing

摘要

The larger power transformers are greatly affected by the DC magnetic biasing phenomenon, which may cause the local overheating and threaten the safe operation of the power transformer. We aimed at studying the temperature distribution and temperature rise in the power transformer under DC magnetic biasing current. A 240000 kVA/330 kA oil immersible power transformer is studied. The 3D model of the power transformer and the DC magnetic biasing injection are established, respectively. According to the calculation of fluid field and the high-voltage winding loss, the temperature distributions of the power transformer are obtained. The results show that the temperature rise and the high-voltage winding loss are greatly affected by the DC magnetic biasing phenomenon.