## 9 Conclusions  
In this paper, based on the modified optimal criteria with the torque-speed performance and the drive efficiency, a computational procedure for the optimization model of a TSF has been described, including the maximization of the torque-speed range and the minimization of copper loss. In addition, by modifying the optimization objective of the \(q\)th-power current, a TSFs family with regard to torque capability is presented and the proposed TSF1 (\(r=4\)) is compared with the conventional TSFs. The torque reference can be directly converted into the current reference using the rewritten torque-current profile model of the SRM either in the linear or the saturation magnetic region. The evaluation indices and the performance of the proposed and the classical methods are compared in terms of peak phase current, rms phase current, and torque ripple factor. The experimental results,  
Figure 17: Harmonic component and phase of the total torque (\(T_{\mathit{ref}}=1.5\) Nm, speed \(=3000\) rpm): (**a**) CCC; (**b**) Linear TSF; (**c**) Sinusoidal TSF; (**d**) TSF1 (\(r=4\)). which match the simulation results very well, show that no matter whether the rotor speed is low or high, the proposed TSF1 (\(r=4\)) has the lowest peak and rms phase current compared with the CCC, the linear, and the sinusoidal TSF. Additionally, the proposed TSF1 (\(r=4\)) has a commutation torque ripple ratio that is one-third less compared to the conventional TSFs in the saturation magnetic region at a speed of 3000 rpm. Moreover, the proposed TSF1 (\(r=4\)) improves the drive efficiency, increases the rotor speed range of the torque-ripple-free operation, and reduces the requirements of the peak and rms phase current. The validity and superiority of the proposed control method have been experimentally proved. [PERSON] and [PERSON] conceived and designed the experiments; [PERSON] performed the experiments under the help of [PERSON]; [PERSON] and [PERSON] analyzed the data; [PERSON] contributed analysis tools; [PERSON] wrote the paper. The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results. * [PERSON] et al. (2005) [PERSON], [PERSON]; [PERSON]; [PERSON] Indirect torque control of switched reluctance motors using iterative learning control. _IEEE Trans. Ind. Electron._**2005**, _56_, 200-208. [CrossRef]
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