## 5 Results: Impact of Faults in LSHT Machines
### Evaluation of Faults Specific to SCIMs: Broken Rotor Bars  
The variation in performance metrics following the different broken bar levels described in Section 3.2.2 is presented in Table 6 for the 10-pole IM. From the results, it can be noted that the presence of broken bars has minimal impact on torque capacity, efficiency, losses, or power factor. However, in the severe case evaluated, i.e., when three rotor bars are broken, a slight reduction in torque and power factor is observed. \begin{table}
\begin{tabular}{c c c c c} \hline  & **Parameter** & **Symbol** & **PMSM** & **SynRM** & **SCIM** \\ \hline \multirow{4}{*}{Healthy} & Mean Torque & \(\mathrm{T_{mean}\;[Nm]}\) & 1522 & 607.7 & 640.1 \\  & Torque Ripple & \(\mathrm{T_{rp}\;[\%]}\) & 2.7 & 45.4 & 10.8 \\  & Efficiency & \(\mathrm{\eta\;[\%]}\) & 96.2 & 90.3 & 90.7 \\  & Active Losses & \(\mathrm{L_{cp+fe+edd}\;[W]}\) & 2358 & 2565 & 2543 \\  & Power Factor & \(\mathrm{pf\;[-]}\) & 0.98 & 0.36 & 0.63 \\ \hline \multirow{4}{*}{Dynamic \(\Delta_{\mathrm{de}}=0.25\)} & Mean Torque & \(\mathrm{T_{mean}\;[Nm]}\) & 1523 & 608.7 & 641.7 \\  & Torque Ripple & \(\mathrm{T_{rp}\;[\%]}\) & 3.0 & 46.3 & 11.1 \\  & Efficiency & \(\mathrm{\eta\;[\%]}\) & 96.2 & 90.3 & 90.7 \\  & Active Losses & \(\mathrm{L_{cp+fe+edd}\;[W]}\) & 2363 & 2568 & 2544 \\  & Power Factor & \(\mathrm{pf\;[-]}\) & 0.98 & 0.36 & 0.63 \\ \hline \multirow{4}{*}{Dynamic \(\Delta_{\mathrm{de}}=0.5\)} & Mean Torque & \(\mathrm{T_{mean}\;[Nm]}\) & 1524 & 612.7 & 649.2 \\  & Torque Ripple & \(\mathrm{T_{rp}\;[\%]}\) & 4.1 & 49.8 & 12.2 \\  & Efficiency & \(\mathrm{\eta\;[\%]}\) & 96.2 & 90.3 & 90.7 \\  & Active Losses & \(\mathrm{L_{cp+fe+edd}\;[W]}\) & 2373 & 2581 & 2560 \\  & Power Factor & \(\mathrm{pf\;[-]}\) & 0.98 & 0.36 & 0.63 \\ \hline \multirow{4}{*}{Static \(\Delta_{\mathrm{se}}=0.25\)} & Mean Torque & \(\mathrm{T_{mean}\;[Nm]}\) & 1522 & 606.6 & 639.5 \\  & Torque Ripple & \(\mathrm{T_{rp}\;[\%]}\) & 3.0 & 44.5 & 10.6 \\  & Efficiency & \(\mathrm{\eta\;[\%]}\) & 96.2 & 90.3 & 90.7 \\  & Active Losses & \(\mathrm{L_{cp+fe+edd}\;[W]}\) & 2361 & 2566 & 2552 \\  & Power Factor & \(\mathrm{pf\;[-]}\) & 0.98 & 0.36 & 0.63 \\ \hline \multirow{4}{*}{Static \(\Delta_{\mathrm{se}}=0.5\)} & Mean Torque & \(\mathrm{T_{mean}\;[Nm]}\) & 1523 & 611.0 & 642.3 \\  & Torque Ripple & \(\mathrm{T_{rp}\;[\%]}\) & 3.9 & 47.7 & 11.6 \\ \cline{1-1}  & Efficiency & \(\mathrm{\eta\;[\%]}\) & 96.2 & 90.3 & 90.7 \\ \cline{1-1}  & Active Losses & \(\mathrm{L_{cp+fe+edd}\;[W]}\) & 2371 & 2579 & 2552 \\ \cline{1-1}  & Power Factor & \(\mathrm{pf\;[-]}\) & 0.98 & 0.36 & 0.63 \\ \hline \end{tabular}
\end{table} 
Table 5: Main performance data comparison of optimized 16-pole LSHT machines including eccentricities faults. The most notable effect of broken bars is observed in the torque ripple, which increases progressively as more bars fail. Specifically, the torque ripple increases by 64%, 169%, and 426% at severity levels 1, 2, and 3, respectively. Table 7 summarizes the variation in the performance metrics after the implementation of the different broken bar severities described in Section 3.2.2 for the 16-pole IM. Results in Table 7 indicate that the presence of broken bars has a negligible effect on the mean torque, efficiency, losses, or power factor of the 16-pole machine. In contrast with the 10-pole machine, the most severe case evaluated did not have a significant effect on torque capacity for the 16-pole machine, likely due to the increased number of rotor bars. The most notable effect of broken bars, similar to that observed for the 10-pole machine, is seen in the torque ripple, which increases progressively as more broken bars are considered. In this 16-pole IM, the torque ripple increases by 16%, 43%, and 124% at severity levels 1, 2, and 3, respectively. Furthermore, it was observed from a torque waveform inspection that the dominant torque ripple harmonics, in the presence of broken bars, are related to the slip value and result from rotor asymmetry.