A Numerical Method for Simulation of Dynamic Hysteresis and Loss Distribution in Transformer Cores Under Complex Operational Conditions

This paper proposes a numerical method combining a fixed-point harmonic balance finite element method (FEM) with a dynamic hysteresis model to accurately calculate the loss distribution of laminated cores under complex operating conditions. This method primarily employs the frequency-domain FEM to solve the magnetic field distribution of silicon steel laminated cores under various excitations, including power frequency multi-harmonic conditions. The resulting magnetic flux density distribution is substituted into the dynamic hysteresis model, enabling the accurate simulation of the hysteresis loop at any position of the laminated core. Hence, the loss distribution of the laminated core can be obtained. Compared to the modified Steinmetz formula, the proposed method is validated with better performance. The relative error is less than 6% between the measured and the calculated core losses of the proposed method. These results can improve the accuracy and efficiency of transformer iron loss calculation in engineering applications.