In this letter, a transformed unsaturated inductance characteristic-based method is proposed for the rotor position of the switched reluctance machine. Due to the magnetic saturation effect, the phase inductance characteristics have a narrow linear region, which increases the difficulty of their analytical expression. To reduce the complexity of the analytical expression, the unsaturated inductance characteristic is transformed from the phase inductance characteristics. Then, a linear model is presented to explicitly describe the relationship between the rotor position and unsaturated phase inductance. Experimental verification is carried out to verify the effectiveness and accuracy of the proposed method. The proposed method can serve as a low-effort way to provide the accurate rotor position for the industry application at medium and high-speed ranges.

Although the torque and radial force ripples are two important causes of unwelcomed vibration in switched reluctance machines, the suppression of these ripples is usually contradictory. To address this issue, we propose a model predictive torque and force control (MPT&FC) method. First, the torque and force sharing functions are constructed based on the flux-linkage curve, following which the sharing functions are optimized online by tuning the turn- on angle to minimize the torque and force ripple. Finally, the MPT&FC method is applied to complete the sharing function tracking control. For balanced control of the torque and radial force, we optimize the candidate-voltage-vector table. Experiments were done on a three-phase 12/8 switched reluctance machine to verify that the proposed method suppresses vibrations.

This article presents a low-measurement effort and less storage space but an effective method to reduce the torque ripple. First, a torque-balanced measurement method is presented to obtain the flux-linkage characteristics at four torque-balanced positions. Then, a four-order Fourier series model is proposed to describe the entire flux-linkage and torque characteristics. To reduce the storage space, a polynomial-Fourier series model is proposed to describe the torque and current model from the rotor position and flux linkage. Based on the proposed polynomial-Fourier series model, a novel model predictive torque control (MPTC) is implemented to minimize the torque ripple with flux-linkage-based torque estimation. Experimental results show that the proposed method can effectively reduce torque ripple with lower measurement effort and less storage space compared with the traditional MPTC method. The proposed method provides a low effort and convenient way to implement the advanced control of SRMs in the industry application.

A new method to detect the initial rotor position of switched reluctance machine (SRM) is presented in this article. Unlike most conventional position estimation methods, the proposed method does not need any extra premeasurement and only the data with finite element method (FEM) are required. First, a linear regression model (LRM) is presented to describe the relationship between FEM and measured inductance characteristics. Then, to detect the position, the residual sum of squares of the proposed LRM is considered as an objective function, which is a convex function with rotor position. The rotor position can be estimated by minimizing the objective function with the golden-section search method. Finally, the accuracy of the proposed estimation algorithm is validated by the experimental results on a three-phase 12/8 pole SRM prototype. Compared with the existing position estimation methods, the proposed method has higher accuracy and less measurement effort. The proposed method can serve as a supplement to provide accurate initial position information for incremental position sensors.

With the increasing focus on sustainable development and environmental preservation, the aviation industry has been exploring innovative solutions, such as more electric aircraft (MEA), to shape the future of air transportation. Among the various machines used in MEA, switched reluctance machines (SRMs) have gained significant attention due to their high reliability and excellent characteristics at high speeds. Delving into the forefront of SRM technologies, this article has summarized the advanced machine design, control strategies, fault diagnosis, and tolerant techniques, and the challenges of SRMs within the context of MEA. This article can provide resources for a deeper understanding of the latest developments in the technologies of SRM and help promote the application and development of SRM in the MEA field.