## 7 Experimental Results  
To verify the practicability of the proposed DPTC method, relevant experimental tests are conducted on the SRM experimental bench. The relevant devices of the experimental bench are shown in Figure 9, which mainly include SRM, SRM controller, power converter, and oscilloscope. The load torque is generated by a magnetic powder brake, and the output torque is controlled by the predefined control algorithm. In the experimental test, the control algorithm is operated by a dSPACE-1103 controller. Because the oscilloscope used has only two channels, only the phase current and total output torque can be captured. In addition, to ensure consistency between the experiment and simulation, the parameters of the algorithms and the specification of the SRM are the same as in the simulation.  
Figures 10-12 show the experimental results of the four methods at 200, 400, and 800 rpm speeds when the load is 5 Nm. From the current waveform of the above methods, it can be seen that the DITC and PWM-DITC still have larger current peaks than the other two methods, which is not expected during the experiment. Moreover, the proposed DPTC method has smoother phase current and phase torque curves than the MPTC method.  
To quantitatively evaluate the experimental results of the above methods, the performance indices \(T_{r,p}\), \(T_{r,RMS}\), and \(I_{RMS}\) have been calculated using (32)-(34) and summarized in Table 3. As can be seen from Table 3, the DITC method still has the largest torque ripple index \(T_{r,p}\) of 42.4%, 51.3%, and 63.8% at 200, 400, and 800 rpm, respectively. Although the torque ripple is optimized in the MPTC method, it is still relatively large at 41.2%, 47.8%, and 56.3%, respectively. Undoubtedly, the proposed DPTC method has a smaller torque ripple than the MPTC method with 22.4%, 33.2%, and 39.4%, respectively. This shows that the proposed method reduces the torque ripple by 45.63%, 30.54%, and 30.02%, respectively, which has a high agreement with the simulation results. In terms of the copper loss, since  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Method** & **Speed (rpm)** & \(T_{r,p}\) & \(T_{r,RMS}\) & \(I_{RMS}\) \\ \hline \multirow{4}{*}{DITC} & 200 & 39.1\% & 0.4359 & 4.6121 \\  & 400 & 42.9\% & 0.4763 & 4.8216 \\  & 800 & 58.4\% & 0.5842 & 5.1493 \\  & 200 & 38.2\% & 0.4043 & 4.3071 \\  & 400 & 41.8\% & 0.4526 & 4.5162 \\  & 800 & 53.2\% & 0.5493 & 5.1201 \\  & 200 & 19.2\% & 0.1365 & 4.6230 \\ PWM-DITC in [36] & 400 & 33.5\% & 0.2437 & 4.8113 \\  & 800 & 39.3\% & 0.3479 & 5.2329 \\  & 200 & 17.9\% & 0.1302 & 4.2109 \\ DPTC & 400 & 29.4\% & 0.2054 & 4.4360 \\  & 800 & 38.6\% & 0.3421 & 4.9058 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Simulation performance comparison at various speeds.  
Figure 9: Experimental bench.  
the PWM-DITC method adheres to the principle of completing the commutation as soon as possible, compared with the proposed DPTC method, it has a higher copper loss index \(I_{RMS}\) of 4.7106, 4.8742 and 5.3400 respectively. In contrast, the proposed DPTC method results in the copper loss index of 4.3065, 4.5218, and 4.9945 by optimizing the demagnetization and magnetization of two consecutive phases. This shows that the proposed method reduces the copper loss index by 8.58%, 7.23%, and 6.47%, respectively. Through the comparison results of the above experiments, the same conclusion as the simulation verification can be concluded, i.e., the proposed DPTC method has relative advantages in the torque ripple and copper loss, and the effectiveness of the proposed method is proved.  
Figure 11: Experimental results of (**a**) the DITC method, (**b**) the FCS MPTC method in [31], (**c**) the PWM-DITC method in [36], and (**d**) the proposed DPTC method at 400 rpm with a load of 5 Nm.  
Figure 10: Experimental results of (**a**) the DITC method, (**b**) the FCS MPTC method in [31], (**c**) the PWM-DITC method in [36], and (**d**) the proposed DPTC method at 200 rpm with a load of 5 Nm.