Sensorless Control of Synchronous Reluctance Machines Combining Active Flux With High-Frequency Injection

This paper proposes a novel sensorless control strategy for Synchronous Reluctance Machines (SynRM) by combining the active q flux with high-frequency injection (HFI). Traditional HFI methods may suffer instability due to magnetic saturation and cross-coupling effects inherent in SynRM. To address this problem, the proposed method utilizes active q flux to enhance excitation saliency and avoid unstable operating regions, thereby improving position estimation robustness. A hybrid control approach is designed, employing HFI at low speeds and switching to an active q flux observer at higher speeds, with a weighted fusion logic ensuring smooth transition. Experimental results verify the effectiveness of the proposed method in achieving accurate and stable sensorless control from standstill to rated speed.