To enhance the mechanical safety, guarantee sufficient temperature margin and reduce the high-frequency electromagnetic interference of the starter/generator embedded in the aero engine, a multi-objective optimization control method is proposed for the switched reluctance machine based on the model prediction and the torque sharing function. For the model predictive control, the instantaneous phase torque is estimated through the Hermite interpolation with the flux-linkage characteristics at the aligned and unaligned rotor position, and the reference phase torque is obtained by the torque sharing function. The error between the estimated and real instantaneous torque, especially around the unaligned rotor position, will result in the performance degradation, which is effectively compensated by the new torque sharing function. The performances of the proposed control method are evaluated in detail by the simulation and experiment, and comparison with other representative methods are carried out as well. 1.

Relatively high torque ripple limits the further development of the switched reluctance machine, and the application of the ripple suppression method will reduce the efficiency of the system. To simultaneously improve the efficiency and torque ripple of the switched reluctance machine, a new commutation and online optimization strategy is proposed. According to the torque per ampere characteristics of the machine, two rotor position angles are defined, which are the boundaries for the high and low torque per ampere operation modes of the two adjacent phases, respectively, and for different operating modes, specific torque hysteresis control schemes are performed. Furthermore, an objective function is constructed with the efficiency and torque ripple coefficient, and during the operation of the machine, the defined boundary angles are online optimized by the genetic algorithm to maximize the value of the objective function. The effectiveness of the method is verified by detailed simulation and experiment under different operating conditions.

According to the modular power converter, a novel phase current reconstruction method using single dc-link current sensor is proposed for 3-phase switched reluctance machine (SRM), and the control method is implemented with the reconstructed phase current as well. A highly integrated modular power converter is constructed by a 3-phase full bridge and a dual switch module. The phase windings are in star-connection, and the bipolar phase currents are applied. Based on the special operating modes and single PWM signal injection, the dc-link current is decoupled and the phase current in both magnetization and demagnetization regions is reconstructed, which is very critical for the implementation of some advanced methods that require complete period phase current. The conventional control methods of the SRM, such as single-pulse voltage (SPV) and hysteresis current control (HCC) method, are carried out under different operating conditions with both simulation and experiment to verify the effectiveness of the proposed method, and the reconstruction errors and performance influences are detailed analyzed as well.

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.