## 4 Results and Discussion
### Scenario II: Unbalanced and Sinusoidal Source Voltage  
In Scenario II, the applied source voltage exhibits a sinusoidal wave-shape, but its magnitude differs across each operating phase (refer to Figure 6b). The simulation findings obtained from this category of testing are presented in Figures 12-16. Meanwhile, to better observe the demonstrated performance, important findings are tabulated in a comparative manner, as in Table 3. First, referring to Figure 12, the enhanced-ADALINE algorithm is revealed to effectively extract the magnitude (mean value) of fundamental load current. Similarly, without integrating the averaging function, a significant peak-to-peak oscillation (ripples) can be observed at the extracted mean value (approximately 0.9 A for Load A and 0.5 A for Load B). However, by integrating the averaging function, the extracted mean value does not exhibit any significant ripples, which indicates a more accurate result. Next, from Figures 13 and 15, the findings revealed that both enhanced-ADALINE and STF-dq0 algorithms are effective in directing their respective SAPF in mitigating the harmonics generated by Loads A and B under Scenario II. For both unbalanced load conditions, the highly distorted source currents which are mitigated by both algorithms recovered the desired sinusoidal wave-shape with THD values (refer to Table 3) maintained within the 5% harmonic limit. Specifically, in terms of the recorded THD values, for Load A, the THD values demonstrated by the enhanced-ADALINE algorithm are lower than that demonstrated by the STF-dq0 algorithm. However, for Load B, the lower THD value of the enhanced-ADALINE algorithm is recorded only for phase \(b\). Although the recorded THD values  
Figure 12: Simulation result obtained under Scenario II, showing the magnitude (mean value) of fundamental load current extracted by the enhanced-ADALINE algorithm with and without integrating Averaging function: (**a**) Load A and (**b**) Load B.  
for phases \(a\) and \(c\) are higher, the difference is actually not significant. Nevertheless, as an overall, the THD values recorded for the enhanced-ADALINE algorithm is of smaller value range, i.e., 0.88-2.63% while the THD values recorded for the STF-dq0 algorithm is of larger value range, i.e., 1.19-2.83%. Moreover, it is also clear from the findings that the high neutral currents that resulted from unbalanced connection of single-phase loads (both Loads A and B) were minimized. In other words, once again, both enhanced-ADALINE and STF-dq0 algorithms are shown to be effective in removing excessive neutral currents. Furthermore, as tabulated in Table 3, for Loads A and B, the large phase differences between the source voltage and current were reduced by both algorithms. Hence, it indicates that both algorithms are able to synchronize operation of the SAPF with the connected power system under Scenario II. Nevertheless, the enhanced-ADALINE algorithm demonstrated a better synchronization performance by providing a lower phase difference value. As a result, in-phase operation of the source current and voltage is once again achieved, and this provides a near to unity power factor (PF) of 0.999. Therefore, as an overall, the enhanced-ADALINE algorithm is able to provide a better mitigation performance in comparison to STF-dq0 algorithm under Scenario II. Similarly, the ability of SAPF to regulate its dc-link voltage is also assessed under Scenario II. Figures 14 and 16 provide the related results. From both figures, SAPF controlled by the enhanced-ADALINE algorithm is able to continuously maintain its dc-link voltage \(V_{dc}\) at the desired voltage level (880 V). Similarly, the individual voltage across each split capacitor \(V_{dc1}\) and \(V_{dc2}\), is equally maintained at the desired voltage level (440 V), i.e., half the value of the total dc-link voltage. The findings are valid for both Loads A and B.