## 2 Simulation Model  
### PV Panel  
The PV array output power can be calculated using the following formulas [26]:  
\[P_{PV} =P_{max}F_{PV}\Bigg{(}\frac{\overline{I_{T}}}{\overline{G_{T,STC}}} \Bigg{)}\Big{[}1\ +\ \alpha_{p}(T_{c}-T_{c,STC})\Big{]} \tag{1}\]  
\[T_{c} =T_{a}+\ G_{T}\Bigg{(}\frac{T_{c,\ NOCT}-T_{a,\ NOCT}}{G_{T,NOCT}} \Bigg{)}\Big{(}1-\frac{\eta_{cell}}{\tau\alpha}\Big{)} \tag{2}\]  
where \(P_{max}\) is the rated capacity of the PV panel (kW); \(F_{PV}\) is the PV derating factor, which is dependent on PV surface conditions such as clearness (%); \(\overline{I_{T}}\) is the incident radiation to the PV surface (kW/m\({}^{2}\)); \(\overline{G_{T,STC}}\) is the incident radiation under standard conditions; \(\alpha_{p}\) refers to the cell temperature coefficient (%/\({}^{\circ}\)C); \(T_{c}\) is the cell temperature; \(T_{c,STC}\) is the PV cell temperature under standard conditions; \(T_{a}\) indicates the ambient temperature; \(T_{c,\ NOCT}\) is the nominal operating cell temperature of the PV module; \(T_{a,\ NOCT}\) is the ambient temperature at the NOCT (nominal operating cell temperature); and \(\eta_{cell}\) is cell efficiency which can be assumed to equal to the maximum power point efficiency \(\eta_{max}\). The main input data used in Equations (1) and (2) are reported in Table 2.  
The relationship between sun path and solar panel ang \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Symbol** & **Value** \\ \hline Temperature coefficient (\%/deg) & \(\alpha_{p}\) & \(-0.258\) \\ \hline Maximum efficiency & \(\eta_{\max}\) & \(0.217\) \\ \hline Rated power (W) & \(P_{max}\) & \(325\) \\ \hline Nominal operation cell temperature (\({}^{\circ}\)C) & T\({}_{c,\ NOCT}\) & \(44\) \\ \hline Nominal operation ambient temperature (\({}^{\circ}\)C) & T\({}_{a,\ NOCT}\) & \(20\) \\ \hline Incident radiation under test condition (W/m\({}^{2}\)) & \(\overline{G_{T,STC}}\) & \(1000\) \\ \hline Derating factor & \(F_{PV}\) & \(0.9\) \\ \hline Cell temperature under test condition (\({}^{\circ}\)C) & \(T_{c,STC}\) & \(25\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Main input data used in the PV output power estimation [27]. Figure 1: Proposed system configuration. The incident radiation to the PV surface is a function of the ambient condition, time, and period of the earth's revolution, which can be calculated by using the equation below [28]:  
\[\mathrm{I_{T}}=\mathrm{I_{grobal}}\left(\left(\cos\psi\cos\kappa+\sin\psi\sin \kappa\cos(\lambda-\zeta)+\mu\cos\frac{\psi}{2}\right)+\rho\left(\cos\kappa+ \mu\sin^{2}\frac{\psi}{2}\right)\right) \tag{3}\]  
where \(\mathrm{I_{grobal}}\) is global irradiance on a surface perpendicular to the vector of sunlight (\(\mathrm{kW/m^{2}}\)); \(\mu\) is diffuse portion constant for calculation of diffuse radiation as a part of incident radiation; \(\psi\) is the tilt angle between the ground, which is parallel to the horizon, and the PV panel; \(\rho\) is the reflection index that is dependent on grounding condition; and \(\lambda\) and \(\zeta\) indicate sun azimuth on the celestial sphere and plate azimuth angle (radians east \(>0\) and west \(<0\)). The sun's zenith angle, \(\kappa\), is the angle between the sun's rays, and the perpendicularity to the horizontal plane can be calculated as follows:  
\[\cos\kappa=\sin\delta\sin\gamma+\cos\delta\cos\gamma\cos\alpha \tag{4}\]  
where \(\delta\) is the solar declination angle on the celestial sphere, which is concerned sun altitude, and \(\gamma\) is the latitude in the observed point. The sun's declination is the angle between a line connecting the center of the sun and earth and the projection of this line on the equatorial plane.