Implementation of Flux Polar Control in IPM Synchronous Motor

Synchronous motor drives are widely employed in high-performance electric applications due to their high torque density, efficiency, and wide operating range. However, achieving effective torque control remains challenging because of magnetic cross-coupling, parameter sensitivity, and the nonlinear behavior of the machine, especially in flux-weakening conditions. Flux Polar Control (FPC) is a control strategy based on the direct regulation of the stator f lux vector in polar coordinates through the independent control of flux magnitude and flux angle. This formulation provides a physically meaningful interpretation of torque production and offers a structured framework for the control of synchronous machines. This thesis presents the modelling, implementation, and simulation-based validation of a Flux Polar Control strategy for synchronous motor drives. A linear Interior Permanent Magnet Synchronous Motor (IPMSM) model is first developed and used as a reference framework for controller design and initial validation. In this case, the stator flux vector is reconstructed through a voltage-model-based flux estimator derived from the stator voltage equations. The implemented control structure includes reference generation for Maximum Torque Per Ampere (MTPA) and flux-weakening operation, together with PI regulation loops, voltage limitation, and anti-windup compensation. In a second stage, the same control architecture is applied to a nonlinear map-based synchronous reluctance motor model, where the machine behavior is described directly through flux-linkage, torque, and differential inductance lookup tables. This allows magnetic saturation and cross coupling effects to be represented more realistically, providing a more demanding validation environment for the controller. The obtained simulation results confirm that the proposed Flux Polar Control structure is capa ble of preserving stable and physically coherent behavior in both linear and nonlinear operating conditions. In particular, the nonlinear implementation reproduces the expected transition from the nominal operating region to flux-weakening conditions, while also highlighting the practical limitations introduced by voltage constraints and nonlinear machine behavior. Overall, the work confirms the viability of Flux Polar Control as a structured and effective control approach for synchronous motor drives and highlights the importance of nonlinear ma chine modelling for a realistic assessment of control performance.