Compact Structurally Constrained Torque Model for IPMSM Drives: Identification, Cross-Machine Validation, and Embedded Implementation

Preprint of a manuscript currently under peer review. This work presents a compact structurally constrained five-coefficient model for the steady-state shaft torque of interior permanent-magnet synchronous motors (IPMSMs). The model is identified directly from samples in the Id-Iq plane using a two-stage procedure based on the observed near-affine dependence of torque on Id at fixed Iq. The proposed representation is validated on independent experimental data, re-identified and tested on five additional PMSM datasets, compared with constant-parameter, polynomial, and lookup-table torque representations, and evaluated in real-time embedded implementation on an ARM Cortex-M4F controller. The software and processed datasets supporting the study are available in the related Zenodo reproducibility package.