## 5 Conclusions  
While aiming at the uncertainties of renewable energy and load demand in a three-phase unbalanced distribution network, a robust control model of automatic load commutation devices considering the uncertainties of source and load is established in this paper. First, based on the historical data of photovoltaic power generation system, wind power generation system, and user load, a forecast analysis is carried out, and the uncertainty models of renewable energy and load demand are established. Then, based on the robust optimization method, a robust control strategy for the automatic load commutation device considering the uncertainties of both source and load is proposed. On this basis, the proposed model is linearized based on second-order cone technology and the strong dual theory to make it easier to be solved. Finally, taking the modified IEEE 33-bus system as an example, case studies are conducted to verify the effectiveness of the proposed strategy. The results verified the feasibility and effectiveness of the proposed method and show that the model proposed in this paper will sacrifice part of the economics of distribution network operation, but it has better adaptability to harsh scenarios and does not have too much economic loss in mild scenarios, which can strengthen the distribution network to cope with the uncertainty of source and load in the network. In addition, by adjusting the deviation and uncertainty parameters of load demand and renewable energy, the robustness and economy of the proposed model can be well balanced. The future work can be carried out from the following aspects:  
1. The selection method of the optimal uncertainty is not considered in this work. The optimal uncertainty can be selected on the basis of the commutation strategy, reasonably reduce the size of the uncertainty set, and weigh the conservatism of the robust control.
2. The whole optimization cycle for optimization is taken as 24 h in this work, which reduces the number of actions of the commutation device. How to reasonably divide the commutation cycle of the load automatic commutation device within a day to further improve the economy of distribution system operation needs to be studied in the future.  
Conceptualization, Y.W., Z.C., T.Z. and Z.L.; methodology, Y.W. and Z.C.; software, Y.W. and Z.C.; validation, G.C.; formal analysis, Y.W. and Z.C.; investigation, G.C. and Z.C.; resources, G.C.; data curation, Y.M.; writing--original draft preparation, Y.W. and Z.C.; writing--review and editing, T.Z. and Z.L.; visualization, T.Z. and Y.M.; supervision, C.C. and Z.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China, grant number U2166206 and the National Natural Science Foundation of China, grant number 5207/195.  
Not applicable.  
The data presented in this study are available from the first author upon request.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} **Uncertainty** \\ **Parameter**\(\mathbf{I_{DG}}\) \\ \end{tabular} } & \multicolumn{3}{c}{**Objective Function Value Corresponding to the Uncertain Parameter \(\mathbf{I_{L}}\)/USD**} \\ \cline{2-4}  & **0.6** & **0.8** & **1.0** \\ \hline
0.6 & 494.76 & 538.32 & 583.33 \\
0.8 & 502.05 & 546.65 & 592.74 \\
1.0 & 509.93 & 555.52 & 602.63 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Impact of uncertainties of load demand and renewable energy on objective function values.