Due to the expected increase in the electric vehicles (EVs) sales and hence the increase of the price of rare-earth permanent magnets, the switched reluctance motors (SRMs) are gaining increasing research interest currently and in the future. The SRMs offer numerous advantages regarding their structure and converter topologies. However, they suffer from the high torque ripple and complex control algorithms. This paper presents an improved direct instantaneous torque control (DITC) strategy of SRMs for EVs. The improved DITC can fulfill the vehicle requirements. It involves a simple online torque estimator and a torque error compensator. The turn-on angle is defined analytically to achieve wide speed operation and maximum torque per ampere (MTPA) production. Moreover, the turn-off angles are optimized for minimum torque ripples and the highest efficiency. In addition, this paper provides a detailed comparison between the proposed DITC and the most applicable torque control techniques of SRMs for EVs, including indirect instantaneous torque control (IITC), using torque sharing function (TSF) strategy and average torque control (ATC). The results show the superior performance of the proposed DITC because it has the lowest torque ripples, the highest torque tor current ratio, and the best efficiency over the low and medium speed ranges. Moreover, the comparison shows the advantages of each control technique over the range of speed control. It provides a very clear overview to develop a universal control technique of SRM for EVs by merging two or more control techniques.

Switched reluctance motors (SRMs) have recently gained notable interest in industrial applications. Yet, their inherent torque ripple poses a significant impediment, limiting the adoption of SRM in high-performance applications. Instantaneous Torque Control (ITC) based on conventional Torque Sharing Function (TSF) is considered a promising technique for torque ripple reduction of SRMs at low speeds. However, the back electromotive force is increased with speed escalation, reducing torque tracking ability to its reference in the ITC based on conventional TSF, especially in the demagnetizing period. The high inductance value in this period opposes phase-current decaying, generating considerable torque ripple, making the ITC unsuitable at medium and high speeds. This paper proposes the indirect ITC based on an improved TSF to address the torque ripple over extended speed for SRM drive. The improved TSF relies on predicting the outgoing phase torque in the demagnetizing period and compensating for the difference between the predicting and reference torque in the next excitation phase by reshaping the incoming phase torque, minimizing the torque ripple. Moreover, simple analytical formulas are used to regulate the control angles to gain further improvements and extended speed. An accurate nonlinear motor model is created based on static magnetic characteristics estimated by the finite element analysis. Several simulated results are conducted to evaluate the effectiveness of the proposed controller. The proposed method offers higher torque ripple mitigation with the speed increase, decreasing the torque ripple by 10% to 45%. Furthermore, the proposed control reduces copper losses and enhances efficiency and torque/current ratio.

Permanent magnet synchronous machines (PMSMs) have garnered increasing interest because of their advantages such as high efficiency, high power density, wide speed range, and fast dynamics. They have been employed recently in several industrial applications including robotics and electric vehicles (EVs). However, PMSMs have highly nonlinear magnetic characteristics, especially interior PMSMs, due to the existence of reluctance torque. Nonlinearity complicates not only machine modeling but also control algorithms. An accurate machine model is the key aspect for the prediction of machine performance as well as the development of a high-performance control algorithm. Hence, this paper presents an accurate modelling method for PMSMs. The proposed model method is applicable for all PMSMs, even multiphase machines. This paper considers a fractional slot concentrated winding 12/10 interior PMSM (IPMSM) for this study to demonstrate the effect of magnetic saturation and special harmonics. The developed model considers accurately the magnetic saturation, mutual coupling, spatial harmonics, and iron loss effects. It utilizes finite element analysis (FEA) to estimate the precise magnetic characteristics of IPMSM. The finite element model is calibrated precisely using experimental measurements. The iron losses are estimated within the simulation model as d- and q-axes current components. The model accuracy is validated experimentally based on a 12/10 IPMSM prototype.