Co-Simulation Comparison Analysis of SPWM and SVPWM in FOC of an Outer Rotor PMSM: Genetic Algorithm Based Optimization for Conventional and Fractional-Order PI Controller

Outer rotor permanent magnet synchronous motors (OPMSMs) are widely preferred in applications requiring high torque at low speeds due to their structural advantages. This study presents a co-simulation-based field-oriented control (FOC) of an OPMSM using ANSYS Maxwell, Twin Builder, and MATLAB/Simulink environments. The motor is modeled using the finite element method in ANSYS Maxwell, while the power electronics and control system are integrated through a co-simulation framework, enabling a realistic and high-fidelity analysis. The main objective of this study is to comparatively evaluate sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) techniques within the same control framework. To enhance the effectiveness and reliability of the FOC controller, a genetic algorithm (GA)-based optimization is employed to tune both conventional PI and fractional-order PI controllers in the speed control loop for the SVPWM method. The findings clearly show that SVPWM beats SPWM in all measured parameters, including current THD, DC-link voltage usage, and torque ripple, which is consistent with the well-known theoretical advantages stated in the literature. Furthermore, the GA-optimized fractional-order PI controller outperforms standard PI controllers in terms of overshoot, settling time, and torque ripple. Overall, the suggested co-simulation framework provides an effective platform for comparing modulation strategies, as well as illustrating the role of GA-tuned controllers in high-performance OPMSM drive systems.