Analytical Model of Magnetic Field of Solid Rotor Induction Motor Considering Saturation Effect

This study develops a hybrid analytical model combining subdomain method and finite difference method (FDM) to overcome conventional limitations in modeling rotor saturation for solid‐rotor induction motors (SRIMs). The solution domain partitions into stator/air‐gap regions solved via subdomain method and rotor region solved via finite difference method with iterative permeability updates, enabling dynamic magnetic field simulation. Validation demonstrates maximum radial flux density errors of 2.43% at s = 0 and 8.26% at s = 1 across the full slip range—significantly surpassing standalone subdomain methods. With computation time reduced by over 90% versus finite element method, the model enables rapid parameter optimization during preliminary electric machine design, providing essential computational efficiency for industrial motor design where accurate saturation modeling is critical. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.