Temperature on metallic parts of Power Transformer due to GIC using FEM based 3D Non-Linear Magnetic Transient Solver

Geomagnetic disturbance (GMD) causes DC current-Geomagnetically induced current (GIC) to flow through the grounded neutral point of star-connected winding power transformer. This can cause significant damage to the transformer installed on power grids. One such major damage is the creation of hot spots in metallic structural parts. Hence, studies regarding the subject of GIC impact on power transformer has sought the attention of researchers. However, there is a significant gap in the calculation methodology adopted to estimate the temperature rise, considering the complexity of the model, non-linearity of metallic parts and the time-dependent electromagnetic problem. Hence, this paper presents 3D finite element based magnetic non-linear magnetic transient simulations to calculate the stray loss increase and surface loss density distribution in structural metallic parts of power transformer due to GIC event. The simulation captures the combined effects of asymmetrical magnetizing caused by DC current, load current and DC current. The simulated surface loss density distribution is then later utilized to calculate the temperature on metallic parts.