## 4 Simulation Results
### Evaluation of the PV System with and Without the Proposed Scheme  
The studied PV system was evaluated in two scenarios: with and without the proposed approach. Since the PV system consists of two distinct parts, MPPT and a Z-source converter, and the main contribution is in the MPPT block, the efficiency of MPPT was investigated. Figure 17 shows the changes in the output power of the usual MPPT system under four different irradiance levels. It is assumed that the DC bus absorbs and consumes any values of incoming power. The rated power of the DC bus was 250 watts. Based on the results from the traditional INC MPPT system, it is observed that at irradiances close to the system's nominal irradiance (\(1000\) W/m\({}^{2}\)), the system takes 0.3 s to establish a stable DC bus voltage, and in relatively weak irradiances, such as under heavy shade, it takes about 0.8 s to establish a stable DC bus voltage. Figure 18 shows the boost control signal under different conditions. Zeroing this signal is equivalent to locking the PWM input pulse in its previous state; otherwise, this signal serves as the PWM input. As can be seen from Figure 18, at lower irradiances, the system's response time and the control signal duration are longer. It should be noted that zeroing the control signal is equivalent to maintaining the previous condition in the subsystem, and the system continues to operate based on the last switching time. Figure 16: Output voltage (Pu) of the studied wind turbine when the wind speed changes from 10 to 15 m/s. Figure 15: Output voltage (Pu) of the studied wind turbine block with a wind speed of 15 m/s. Figure 19 illustrates the system's performance under reduced irradiance from sunny to shaded conditions. In the case of a moderate shade, the system can reach a steady state within 0.3 s. However, it takes about 1 (one) second under heavy shade conditions to reach a steady state, and the system's output power also significantly decreases. A prolonged distortion in the range 1250-750 W/m\({}^{2}\) can adversely affect the quality of DC voltage and, consequently, the grid voltage profile, reducing voltage quality. Figure 19b depicts the changes in output during increasing solar radiation, i.e., exiting from the shade. In the case of light shade, the transition to relatively high irradiation occurs quickly, and in the case of exiting from complete shade, it occurs in less than 0.4 s. In this case, the output distortion is lower than in the previous case, indicating a better performance of the MPPT  
Figure 17: Output power of the studied PV system, including the usual INC MPPT under different irradiance levels. Figure 18: Boost control signal under different conditions: **(a)** 900, **(b)** 1000, **(c)** 1100, and **(d)** 1200 W/m\({}^{2}\). control under increasing solar radiation. Figure 20 compares two increasing and decreasing irradiation scenarios under similar conditions. It demonstrates that for relatively small changes (Figure 20b), the system's response time is similar for both scenarios. However, when the irradiance undergoes a significant change and enters the cell's relatively off state (Figure 20a), the system's response to increasing irradiation exhibits less distortion than decreasing irradiation. By applying the proposed approach and predicting MPP, the duty cycle of the boost controller can be estimated and implemented into the system without needing an additional controller. In this scenario, the MPPT block (Figures 8 and 9) is eliminated, and the subsystem block directly determines the duty cycle of the boost controller based on the predicted MPP. To evaluate the PV system's performance against the conventional system, four comparative plots were built (see Figure 21), illustrating their behavior in both shadow-exit and shadow-entry scenarios. As the light irradiation increased--i.e., exiting the shadow--the conventional system exhibited relatively low distortion; however, the proposed method was faster and had significantly lower distortion.