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In this article, a novel model predictive torque control (MPTC) method for switched reluctance machines (SRMs) is proposed based on the equivalent linear SRM model and the improved switching table. First, an improved switching table with only six switching states is developed based on the inductance characteristics. The adoption of this improved switching table not only reduces the computational burden by 25% but also improves the torque control performance and system efficiency at high-speed region. However, the look-up-table (LUT) based MPTC methods suffer from occupying numerous storage space. To ease this issue, the simple linear SRM model is utilized. The flux-linkage and torque equivalent transformations are introduced to address the difference between the linear and nonlinear SRM models. With these transformations, the MPTC realized on the linear SRM model is proposed. Compared to 1530 storage units consumption to store three two-dimensional (2-D) LUTs in the LUT-based MPTC methods, the proposed method only occupies 228 storage units. Experimental results on an 8/6 SRM setup verify that the proposed method effectively eliminates the commutation torque ripple with lower execution time, less storage space, and improves the torque control performance at a high-speed range compared with the conventional LUT-based method. [ABSTRACT FROM AUTHOR]

In this article, a general-purpose low-speed position estimation scheme using pulse injection is proposed for sensorless switched reluctance motor (SRM) drives. For the conventional low-speed sensorless control methods, magnetic characteristics are often used for position estimation, but it requires offline measurement and reduces the generality of sensorless control algorithms. To solve the issue, a new position estimator based on a regional phase-locked loop (RPLL) is designed. The approach utilizes a self-commissioning process to capture the unsaturated inductance adaptively at the initial stage. The RPLL is then adopted to estimate the full-cycle rotor position from the idle-phase inductance during sensorless operation. The speed-reversible sensorless control capability is also realized by a simple heterodyne design. Furthermore, stability analyses and parameter design are given to prove the robust local stability and convergence. Finally, comparative experimental validation is conducted on a 5.5-kW 12/8 SRM setup to verify the proposed method's effectiveness under both no-load and load conditions. [ABSTRACT FROM AUTHOR]

This paper proposes a novel dynamic torque estimation method, which can quickly and accurately obtain the instantaneous torque with an online calculation based on the local linearization of the energy conversion loop on the flux linkage-current plane of the switched reluctance machine. According to the real-time information of the points on the loop, six situations are illustrated and analyzed. For each situation, the output mechanical energy is obtained first by calculating the area of the corresponding segmented regions, and then, the instantaneous torque is obtained by the difference algorithm concerning the output mechanical energy and rotor position. For the entire process, the unsaturated phase inductance of the machine, which can be conveniently measured, is the only information required in advance. To verify the effectiveness of the proposed method, detailed simulations and experiments are performed under different operating conditions. [ABSTRACT FROM PUBLISHER]