*5.2. Comparison of Voltage Deviation and Power Losses before and after the BESS Installation*

After the BESS installation at the 6th bus, it was found that the value of *%VDI* was maximum at the 33rd bus for the base case (without BESS), GA, and PSO at 6.50%, 4.23%, and 4.22%, respectively. The *%VDI* values of the overall distribution network for all three cases are expressed in Table 2. The BESS installation by using PSO gave the minimum *%VDI* value, which means that PSO could better improve the voltage profile in the distribution network than those of the base case and GA. In Figure 4, the voltage profiles at the 33rd bus for 24 h for all three cases are presented to show how the voltage profile was improved when the BESS was installed by comparing the performance of GA and PSO to the base case. It was observed that the voltage profile of the distribution network was below the lower limit for the base case while it was improved to be within the constraint after the installation of the BESS for both GA and PSO. For the power losses shown in Table 2, it was noticed that power losses could be significantly reduced after the BESS installation compared to the base case. It could also be noticed that the BESS installation by GA provided the minimum values of active power and apparent power while the reactive power loss obtained from GA was equal to that of PSO. However, the power losses obtained from GA and PSO after the BESS installation were slightly different.



**Figure 4.** Voltage profile at the 33rd bus.
