Modeling and Simulation of a 132/33 kV, 63 MVA Transformer Using the Jiles–Atherton Hysteresis Model for Inrush Current Analysis and Protection Enhancement

Power transformers exhibit nonlinear magnetic behavior that significantly affects their transient response during energization, particularly through magnetizing inrush currents that may exceed 6-8 times the rated current.This study develops a detailed simulation model of a 132/33 kV, 63 MVA three-phase transformer using the Jiles-Atherton (JA) hysteresis model to accurately represent core saturation, residual flux, coercivity, and irreversible magnetization.The JA parameters were optimized by minimizing the error between simulated and factory test results.The final calibrated model achieved excellent agreement with manufacturer data, with a magnetizing current error of 0.54% (3.68A simulated vs. 3.70 A factory) and a core loss error of 0.27% (220.9 kW simulated vs. 221.5 kW factory).The model was applied to analyze inrush current behavior under various switching conditions.Without control, the peak inrush current reached values typical of 6-7 pu and exhibited strong asymmetry due to residual flux.To mitigate this, a Smart Reclosing Strategy (SRS) based on JA-derived residual flux prediction was introduced.Simulation results show that optimal reclosing at 45° reduces peak inrush magnitude by more than 50% compared with traditional 0° closing, while significantly improving waveform symmetry and damping characteristics.These results confirm that the combination of high-fidelity JA hysteresis modeling and an optimized reclosing strategy enhances transformer transient prediction accuracy, reduces inrush-related mechanical and electrical stress, and improves protection system selectivity.