## 1 Introduction
### Selecting Direct Torque Control Imitation Model
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & \multicolumn{4}{c}{**Number of Undamaged Windings of Phase A of the Stator**} \\ \cline{2-6}
**Parameter** & \multicolumn{4}{c}{**Winding (Z, \%)**} \\ \cline{2-6}  & **100** & **95** & **90** & **85** & **80** \\ \hline Instantaneous value of the stator current of phase A Is\({}_{\text{ax}}\), A & 636 & 656.27 & 678.4 & 701.45 & 725.74 \\ \hline Instantaneous value of the stator current of phase B Is\({}_{\text{gb}}\), A & 636 & 644.13 & 653.19 & 662.45 & 672.23 \\ \hline Instantaneous value of the stator current of phase C Is\({}_{\text{yy}}\), A & 636 & 645.31 & 654.63 & 663.94 & 673.25 \\ \hline Instantaneous value of the stator flux linkage of phase A \(\psi_{\text{sx}}\), A & 3.952 & 3.93 & 3.914 & 3.895 & 3.876 \\ \hline Instantaneous value of the stator flux linkage of phase B \(\psi_{\text{sS}}\), A & 3.952 & 3.96 & 3.969 & 3.979 & 3.99 \\ \hline Instantaneous value of the stator flux linkage of phase C \(\psi_{\text{sy}}\), A & 3.952 & 3.96 & 3.969 & 3.979 & 3.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Values of the phase currents and flux linkages of the motor at different stages of the damage of phase A of the stator winding and the symmetric system of the feed voltages. Figure 4: Dependencies of currents (**a**) and flux linkages of the stator (**b**) on the number of intact turns of the stator phase A winding in case of the feed symmetry in the steady-state mode. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & \multicolumn{4}{c}{**Deviation of Phase A Voltage from the Nominal**} \\ \cline{2-6}
**Parameter** & \multicolumn{4}{c}{**Value (\(\gamma\), \%)**} \\ \cline{2-6}  & **+2** & **+1** & **0** & **\(\mathbf{-1}\)** & **\(\mathbf{-2}\)** \\ \hline Instantaneous value of the stator current of phase A Is\({}_{\text{ax}}\), A & 667.125 & 651.563 & 636 & 620.438 & 604.875 \\ \hline Instantaneous value of the stator current of phase B Is\({}_{\text{gb}}\), A & 623.992 & 627.826 & 636 & 635.031 & 638.915 \\ \hline Instantaneous value of the stator current of phase C Is\({}_{\text{yy}}\), A & 625.834 & 628.789 & 636 & 634.622 & 637.823 \\ \hline Instantaneous value of the stator flux linkage of phase A \(\psi_{\text{sx}}\), A & 3.988 & 3.968 & 3.952 & 3.934 & 3.917 \\ \hline Instantaneous value of the stator flux linkage of phase B \(\psi_{\text{sS}}\), A & 3.97 & 3.962 & 3.952 & 3.942 & 3.933 \\ \hline Instantaneous value of the stator flux linkage of phase C \(\psi_{\text{sy}}\), A & 3.97 & 3.962 & 3.952 & 3.942 & 3.933 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Values of the phase currents and flux linkages of the stator at different deviations of the phase A voltage amplitude from the nominal value in the case of symmetric windings of the motor stator. As suggested in Figure 4, the dependences of the currents and stator flux linkages on the number of intact winding turns of the stator are of linear nature. It should also be noted that with the increasing number of damaged winding turns (decreasing number of intact ones), the phase current of the damaged winding increased at a higher rate than that of the intact ones. The stator flux linkage of the damaged winding decreased in the case of flux linkages with an increasing number of damaged windings, and increased in the case of the increasing number of intact phases. It should be noted that the phase flux linkages of the intact stator phases were the same, i.e., \(\psi_{\text{sb}}=\psi_{\text{sc}}\). Investigation of the Effect of Asymmetry of the Feed Voltage System under the Conditions of Symmetry of the Motor Windings  
In the investigation of the effect of asymmetry of the feed voltage system on the starting characteristics of the asynchronous motor under the conditions of symmetry of the stator windings, the following adjustments were made in the simulation model. Respective variations of the amplitude were entered into the sinusoidal voltage source of phase A U\({}_{\text{s}\alpha}\).