## 3 Simulation
### Simulation Scenario  
The scenarios conducted in this study are categorized into two main cases, as summarized in Table 7. Each scenario was designed to evaluate the effectiveness of the proposed algorithm by comparing its performance against conventional methods, such as LIFO and Pro-rate control strategies. In Scenario 1, the effectiveness of resource grouping is analyzed by controlling only the PV output within the VPP, without controlling ESS, EV, or FC. The assumed fault for this scenario is a single-line-to-ground fault occurring at Bus 01635, located at the feeder head. The fault resistance is set at 100 ohms. In Scenario 2, the focus shifts to controlling ESS, EV, and FC while leaving the PV output unchanged. This scenario examines the effectiveness of resource grouping in cases where voltage violations are caused by load fluctuations rather than faults. The voltage control range for both scenarios is set between 0.908 p.u. and 1.039 p.u. ; any voltage exceeding this range is classified as overvoltage, while any voltage falling below this range is identified as undervoltage. The base case for the simulation scenarios was developed using the load pattern shown in Figure 6a and the solar irradiance data presented in Figure 6b. This base case incorporates the variations in load patterns and solar irradiance over a 24 h period, reflecting the resulting PV output fluctuations. The base case serves as the reference point for analyzing the performance of the simulation scenarios, providing a realistic representation of daily variations in VPP operational conditions. \begin{table}
\begin{tabular}{c c} \hline \hline
**Type** & **Description** \\ \hline Step Size & 1 h \\ Simulation Time & 24 h \\ Solver & OpenDSS Power Flow Analysis Module \\ Dead-band & 0.908–1.039 [p.u.] \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Simulation parameter. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Scenario** & **Method** & **Assumed Fault** & **Control Element** \\ \hline \multirow{4}{*}{Scenario1} & LIFO & \multirow{4}{*}{Single line-to} \\  & Pro-Rata(C) * & & ground fault \\ \cline{1-1}  & Proposed Algorithm & & \\ \hline \multirow{4}{*}{Scenario2} & LIFO & \multirow{4}{*}{Load fluctuation} & \multirow{2}{*}{ESS, EV, FC} \\  & Pro-Rata(C) & & \\ \cline{1-1}  & Proposed Algorithm & & \\ \hline \hline \end{tabular}  
* Pro-Rata(C) refers to Current Active Output-based Pro-Rata, while Pro-Rata(M) denotes Maximum Active Output-based Pro-Rata.  
\end{table} 
Table 7: Scenario. PV6; at 2 PM, it was applied from PV1 to PV5; and finally, at 3 PM, curtailment affected PV1 to PV4. The reason for the difference in the maximum curtailed amounts per PV unit at 3 PM compared to 1 PM and 2 PM is due to a slight decrease in solar irradiance. While the solar irradiance was at 100% during 1 PM and 2 PM, it dropped to 99% at 3 PM, resulting in reduced power output from the PV units. The voltage results based on the LIFO method are presented in Table 9. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Time**} & \multicolumn{8}{c}{**Curtailment [kWh]**} \\ \cline{2-10}  & **PV1** & **PV2** & **PV3** & **PV4** & **PV5** & **PV6** & **PV7** & **PV8** & **Total** \\ \hline
1 PM & 828 & 828 & 828 & 828 & 828 & 828 & 828 & 828 & 6624 \\
2 PM & 748 & 748 & 748 & 748 & 748 & 748 & 748 & 5984 \\
3 PM & 322 & 322 & 322 & 322 & 322 & 322 & 322 & 322 & 2576 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Curtailment results for the Pro-Rata method in Scenario 1. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Time**} & \multicolumn{8}{c}{**Curtailment [kWh]**} \\ \cline{2-10}  & **PV1** & **PV2** & **PV3** & **PV4** & **PV5** & **PV6** & **PV7** & **PV8** & **Total** \\ \hline
1 PM & 2000 & 2000 & 2000 & 2000 & 2000 & 142 & 0 & 0 & 10,142 \\
2 PM & 2000 & 2000 & 2000 & 2000 & 1670 & 0 & 0 & 0 & 9670 \\
3 PM & 1980 & 1980 & 1980 & 742 & 0 & 0 & 0 & 0 & 6682 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Curtailment results for the LIFO method in Scenario 1.