## 5 Prediction and Analysis of Maximum Temperature Rise
An aluminum bronze slot wedge can improve the eddy current distribution at the rotor end and close to the big teeth when the generator operates asymmetrically. Similarly, other alloy slot wedges with high mechanical strength and good electrical conductivity can also achieve similar effects. However, the large generator rotor is forged from whole rotor steel (as shown in Figure 4), so the negative-sequence current flows not only on the slot wedge but also on the rotor teeth. Due to the asymmetry of the rotor structure, the presence of big teeth will make the current on the slot wedge and teeth present with uneven distribution. Therefore, it is necessary to study the temperature rise and its distribution law of the main structural parts when different slot wedge materials are used. The 300 MW generator studied in this paper has 10% steady-state negative-sequence capacity. Therefore, this paper summarizes the distribution law of the maximum temperature rise of rotor components using different slot wedge materials through the systematic research and analysis of a turbo-generator under different negative-sequence component proportions, and applies negative-sequence currents with negative-sequence component proportions of 1% to 10%, respectively (i.e., \(I_{2}\) = 1% \(I_{N}\), \(I_{2}\) = 2% \(I_{N}\),..., \(I_{2}\) = 10% \(I_{N}\)). In order to find out the change characteristics and effective law of slot wedge materials, this paper studied an aluminum slot wedge, a beryllium bronze slot wedge, and an aluminum bronze slot wedge. The prediction results of the maximum temperature rise based on the ILoTFWA-CPRNN model are shown in Table 4.  
The prediction results in Table 4 clearly indicate that even if the same slot wedge material and the same structure are used, the temperature rise caused by negative-sequence current does not change correspondingly. In a steady-state situation, the smaller the negative-sequence component, the smaller the temperature rise caused by it; the larger the negative-sequence component, the sharper the temperature rise caused by it. When the negative-sequence current varied between 1% and 5%, the difference in the temperature-rise estimate was approximately 1.3 \({}^{\circ}\)C. Similar situations also occurred in the range of 6% \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Position**} & \multirow{2}{*}{**Wedge Material**} & \multicolumn{8}{c}{**Negative-Sequence Component Proportion**} \\ \cline{3-11}  & & **1\%** & **2\%** & **3\%** & **4\%** & **5\%** & **6\%** & **7\%** & **8\%** & **9\%** & **10\%** \\ \hline \multirow{3}{*}{Big tooth} & Aluminum & 12.4 & 12.6 & 12.9 & 13.3 & 13.7 & 14.5 & 15.8 & 17.4 & 19.5 & 23.1 \\  & Beryllium bronze & 15.2 & 15.4 & 15.7 & 16.0 & 16.6 & 17.7 & 19.1 & 20.8 & 23.0 & 27.1 \\  & Aluminum bronze & 19.0 & 19.1 & 19.4 & 19.8 & 20.5 & 21.8 & 23.3 & 24.9 & 26.8 & 30.4 \\ \hline \multirow{3}{*}{Damping slot wedge} & Aluminum & 13.3 & 13.5 & 13.8 & 14.1 & 14.6 & 15.6 & 17.2 & 18.7 & 20.9 & 24.3 \\  & Beryllium bronze & 16.1 & 16.5 & 16.7 & 17.2 & 17.8 & 18.9 & 20.4 & 21.9 & 24.2 & 29.1 \\  & Aluminum bronze & 20.0 & 20.2 & 20.5 & 20.9 & 21.3 & 22.7 & 24.1 & 25.6 & 27.5 & 31.4 \\ \hline \multirow{3}{*}{Slot wedge} & Aluminum & 3.5 & 3.6 & 3.8 & 4.2 & 4.6 & 5.6 & 6.9 & 8.6 & 10.7 & 14.5 \\  & Beryllium bronze & 6.7 & 6.8 & 7.1 & 7.4 & 7.9 & 9.2 & 10.6 & 12.1 & 14.3 & 18.0 \\  & Aluminum bronze & 10.3 & 10.4 & 10.6 & 10.9 & 11.5 & 13.1 & 14.7 & 16.3 & 18.4 & 22.6 \\ \hline \multirow{3}{*}{Small tooth} & Aluminum & 2.9 & 3.1 & 3.4 & 3.8 & 4.3 & 4.8 & 6.1 & 7.5 & 9.6 & 13.7 \\  & Beryllium bronze & 5.8 & 6.0 & 6.3 & 6.7 & 7.4 & 8.1 & 9.4 & 10.8 & 12.7 & 16.8 \\ \cline{1-1}  & Aluminum bronze & 9.1 & 9.3 & 9.6 & 9.8 & 10.9 & 12.2 & 13.6 & 15.2 & 17.1 & 21.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The maximum temperature-rise prediction results, when negative-sequence component proportion changes from 1% to 10%, under the condition of using different wedge materials.