## 3 Simulation Results
### Fuzzy Logic System Results  
In this subsection, we continue with the FLC algorithms results. Therefore, Figure 16 presents an output characteristic of the solar panel showing the voltage, current, and power, the latter two varying concerning the irradiance. Figure 14: Output inverter current, inverter voltage, and grid voltage (InC). Figure 15: The extracted power (Pin) and active power (Pout-IC), transferred by the inverter (InC). Improving characteristics of the solar panel by adding fuzzy logic leads to an increase in the efficiency of the photovoltaic system. Thus, the DC power can be stored almost entirely by the inverter and converted into AC power. The previous image (Figure 17) presents the output characteristics of the inverter (I_inv, V_grid, V_inv). The current tracks the power signal, respecting the irradiance's change one more time. Figure 16: Effect of irradiance on the characteristics of the solar panel (FLC). In the first stage, a comparison was made between the voltage (V_PV), current (I_PV), and power (Pin) characteristics obtained at the output of the solar panel, corresponding to the two methods; this being presented in Figures 13 and 16. Taking the characteristics one by one and comparing them, we can see the difference between the two approaches, which are not negligible. The InC output solar panels characteristic has a pronounced transient regime, significant oscillations, and the maximum voltage is not reached, whereas if we analyze the FLC solar panel characteristics, we notice a fast response, the transient regime is almost non-existent, and the maximum voltage is reached without problems. Making the same comparative analysis between the output characteristics of the inverter, we again notice that the FLC method improves the regime transient, rapid response, elimination of oscillations, and overgrowths corresponding to the InC system. The following figure (Figure 18) illustrates the power-transfer performance. The output power of the solar panel (Pin) is between 149.8 W and 150.2 W, and the active power (Pout-FLC) is between 149.5 and 149.9 W at 1000 W/m\({}^{2}\) irradiance. Therefore, the system based on fuzzy logic has an efficiency of around 99.80%. Figure 19 shows the output voltage of the fuzzy MPPT controller. At the initial time, when the maximum irradiance value is 1000 W/m\({}^{2}\); the _Vmppt_ voltage is 34.8 V. If the irradiance goes down to 500 W/m\({}^{2}\), there is a slight drop in voltage to 34.5 V, which would correspond to the new maximum power point. Therefore, it can be seen that the inverter reference voltage (_Vmppt_) is constant at constant irradiance and has very small variations with irradiance changes; this demonstrates that the fuzzy-based MPPT algorithm provides high accuracy in determining the maximum power point. The grid synchronization signal (_wt_) from the SOGI-PLL loop output is shown in Figure 20. The synchronization signal will have the peak amplitude at 2\(\pi\), as seen in the picture below. Figure 21 shows an overlap of power characteristics at the output of the inverter (Power Out), obtained after simulating the PV system based on the incremental conductance MPPT algorithm (Pout-IC) and the system based on fuzzy logic (Pout-FLC). The green characteristic represents the power obtained at the inverter output within the InC system. Figure 18: The extracted power (Pin) and active power (Pout-FLC), transferred by the inverter (FLC). The orange characteristic represents the power obtained at the inverter output within the FLC system. The green feature has a high transient regime (about 10% of the simulation time), and after that, the feature shows quite pronounced oscillations and overgrowth when changing the irradiance. This involves power losses at the inverter output, which shows that the system implemented with incremental conductance is less efficient. The orange characteristic shows a prompt response, the transient regime being almost eliminated; it does not show oscillations and overgrowths at the sudden irradiance change.