## 5 Results and Discussion
### Results of 69-Bus Radial Distribution System  
Similarly, as before in 33-bus system, there are three parts to be analyzed; base case, DNR and DNR with DG sizing. At each part, the analysis is divided into three different load levels. Meanwhile, the comparison of the effectiveness of the proposed method is compared with the base case, PSO and IPSO. Table 5 shows the base case without reconfiguration and DG placement. In light load level (50% of nominal load), the total power loss is 53.24 kW, while the minimum VSI is 0.8351. For nominal load level, the total power loss is 229.73 kW, with the minimum VSI is 0.6799. Meanwhile, at heavy load level (150% of nominal load), the total power loss is 573.24 kW with minimum VSI is 0.5321. The VSI value is inversely proportional with total power loss. By increasing the load levels, the total power loss is increased significantly and the system becomes unstable. On the other hand, Table 6 summarizes the performances of three optimization technique in DNR for switches, TPL, VSI, voltage profile, and computational time for three different load levels (see Table 6). From Table 6, IEPSO technique gives the best optimal solution with the lowest power losses, improved VSI and computational time as indicated in bold for all load conditions. The increased in load levels, gave results in increasing power losses and decreasing VSI. For light load in case 2 IEPSO technique gave the most reduction in TPL by 64.69%, 11.34% highest VSI, but slightly defeated in computational time compared to IPSO by 0.7 s at light load. Meanwhile, for nominal load in case 2 IEPSO technique gave the most reduction for TPL by 73.06%, 26.14% highest VSI, but slightly defeated in computational time compared to IPSO by 0.98 s at nominal load. Finally, for heavy load in case 2 IEPSO technique gave the most reduction for TPL by 74.95%, 49.03% highest VSI, but slightly defeated in computational time compared to IPSO by 0.68 s at heavy load. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Cases**} & \multicolumn{4}{c}{**Load Levels**} \\ \cline{3-5}  & & **Light Load** & **Nominal Load** & **Heavy Load** \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Case 1: Before \\ reconfiguration \\ (Base Case) \\ \end{tabular} } & Switches & 69, 70, 71, 72, 73 & 69, 70, 71, 72, 73 & 69, 70, 71, 72, 73 \\  & TPL (kW) & 53.24 & 229.73 & 573.24 \\  & VSI min & 0.8351 & 0.6799 & 0.5321 \\  & Voltage Profile min (p.u.) & 0.9560 & 0.9081 & 0.8541 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Base case at different load conditions for 69-bus system. Table 7 summarizes the performances of three optimization techniques in DNR with DG sizing simultaneously for switches, TPL, VSI, voltage profile, DG sizing and computational time for three different load levels. From Table 7, the IEPSO technique gives the best optimal solution with the lowest power losses, improved VSI and computational time as indicated in bold for all load conditions. The increased in load levels, gave results in increasing power losses and decreasing VSI. For light load in case 2 IEPSO technique gave the most reduction for TPL by 66.19%, 15.54% highest VSI, and the fastest in computational time compared to other techniques at light load. Meanwhile,