MRAS-Based Speed Estimator for Sensorless Control of Hybrid Magnetic Circuit PMSM

This paper investigates the application of Model Reference Adaptive System (MRAS) estimators for sensorless control of the Hybrid Magnetic Circuit Permanent Magnet Synchronous Motor (HMC-PMSM), a topology with complex flux paths and sensor placement challenges. Two MRAS structures, flux-based and current-based, are designed and assessed by simulation. Both estimation methods yield precise results for the rotor’s position. However, the flux-based MRAS exhibits smaller speed ripples due to the inherent low-pass filtering effect, whereas the current-based MRAS shows a faster dynamic response at low speeds but with more pronounced speed ripples. The MRAS framework is simple and reduces computational load, making it suitable for real-time embedded motor drives. Although parameter sensitivity, particularly in dual-stator PMSM, can affect MRAS accuracy, this work focuses on evaluating baseline performance under nominal conditions, leaving sensitivity analysis for future research. The results validate the effectiveness of MRAS estimators in achieving reliable sensorless control of HMC-PMSMs and offer insight into rotor position estimator selection for sensorless control of emerging hybrid magnetic circuit PMSM designs.