## 3 Results and Discussion
### Optimization Results Using PSO without and with DG integration
#### 3.2.6 Scenario 6: Three DGs Placed at Buses 18, 33 and 32 Based on the CF Ranking Method  
When the number of DGs integrated into the system was increased to three with locations at buses 18, 33 and 32, the load-flow solution provided the voltage profiles presented in Table 8 for the network under consideration. As can be seen from the results, the voltage profiles were seriously enhanced, thereby providing a better security margin for the system. The minimum voltage was 0.9960 pu at bus 28 while the maximum voltage was 1.0224 pu at bus 14. Also, the power loss associated with this situation was found to be 0.2045 MW. This represents a significant reduction in system power losses of \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Bus No.** & \begin{tabular}{c} **Bus Voltage Profile** \\ **with No DG (pu)** \\ \end{tabular} & \begin{tabular}{c} **Bus No.** \\ **with DG (pu)** \\ \end{tabular} & \begin{tabular}{c} **Bus Voltage Profile** \\ **with No DG (pu)** \\ \end{tabular} & \
\begin{tabular}{c} **Bus Voltage Profile** \\ **with DG (pu)** \\ \end{tabular} &
\begin{tabular}{c} **Bus Voltage Profile** \\ **with DG (pu)** \\ \end{tabular} \\ \hline  
& \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Voltage profile without and with the integration of two DGs at suitable locations (buses 18 and 33) based on the CF ranking values in the IEEE 33-bus distribution system. 80%. Compared with the base case scenario, it can be seen that the power loss was also significantly minimized. With the three DGs integrated at these locations (18, 33 and 32) identified by the CF ranking method, the system operation was significantly optimized such that the voltage profile was improved and power losses reduced to the bare minimum. In this scenario, two arbitrary locations where two DGs could be integrated were selected, which were buses 16 and 32. The results obtained for the system voltage profile, considering this system operating condition, are presented in Table 7. It can be seen from the results in Table 7 that the integration of two DGs at locations (buses 16 and 32) that were arbitrarily selected led to a slight improvement in the general voltage profile of the system. The six scenarios considered and their impact on the network topology are summarized in Table 9. The DG sizes and numbers, DG locations, power losses, minimum voltages \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Bus No.**} & \multirow{2}{*}{\
\begin{tabular}{c} **Bus Voltage Profile** \\ **with No DG (pu)** \\ \end{tabular} } & \multirow{2}{*}{**Bus Voltage Profile**} & \multirow{2}{*}{**Bus No.**} & \multirow{2}{*}{
\begin{tabular}{c} **Bus Voltage Profile** \\ **with No DG (pu)** \\ \end{tabular} } & \multirow{2}{*}{**Bus Voltage Profile**} & \multirow{2}{*}{**Bus Voltage Profile**} \\  & & & & & **with DG (pu)** \\ \hline  
& \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Voltage profile without and with the integration of two DGs at arbitrarily selected locations (buses 16 and 32) in the IEEE 33-bus distribution system. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Bus No. **} & \multirow{2}{*}{\ \begin{tabular}{c} **Bus Voltage Profile** \\ **with no DG (pu)** \\ \end{tabular}  } & \multirow{2}{*}{**Bus Voltage Profile**} & \multirow{2}{*}{**Bus No. **} & \multirow{2}{*}{ \begin{tabular}{c} **Bus Voltage Profile** \\ **with No DG (pu)** \\ \end{tabular}  } & \multirow{2}{*}{**Bus Voltage Profile**} & \multirow{2}{*}{**Bus Voltage Profile**} \\  & & & & **with No DG (pu)** \\ \hline
1 & 1.0000 & 1.0190 & **18** & **0.8297** & **0.9990** \\
2 & 0.9952 & 1.0001 & 19 & 0.9944 & 1.0001 \\
3 & 0.9824 & 1.0103 & 20 & 0.9885 & 0.9994 \\
4 & 0.9704 & 1.0120 &  
and maximum voltage deviations obtained for the six cases and case types considered are presented in Table 9. The six cases considered are depicted in Figure 5 for easy comparison.