## 2 Materials and Methods  
### Construction of Simulation Model in Matlab Package  
Based on the internal structure diagram of the half-cell PV module, which is shown in Figure 1b, a simulation model was designed and implemented in the Matlab/Simulink engineering calculation package using the dedicated solar cell component (Figure 2). This component in the proposed model replaces the half cells, which requires the adoption of half the current intensity for the calculation in relation to the entire cell. In each of the six sections (A\(\div\)F--Figure 1b) of the PV module, a series connection of two \"Solar Cell\" components has been modeled, which replaces four and sixteen halves of PV cells, respectively, which is indicated in Figure 2 in Section D. The structure of the simulation model corresponds to the accepted methodology of verification tests, in which measurements of current-voltage characteristics at partial shading were planned (Figure 3). For the simulation calculations, the parameters of the PV module from the half-cell model--JAM60S03-320/PR (JA Solar, Beijing, China)--were adopted, which are given in Table 1. Environmental parameters (module temperature and solar radiation intensity) in the simulation model were adopted in the same way as during verification tests (Table 2), during which they were registered by the I-V 400 meter (HT Italia SRL, Faenza, Italy). In the methodology of simulation tests, a simplifying assumption was adopted, consisting in the fact that a constant temperature value, measured during verification tests in the geometrical center of the reverse part of the PV module, was introduced into the model (in the properties of the solar cell component). The temperature distribution is uneven, but this effect is evident after prolonged shading and during the study (short measurement time) it was not observable. The solar cell component of the Matlab/Simulink package is based on five parameters of the replacement model, determined in STC. This method is simpler than various complicated determination algorithms described in other works [29; 30; 31]. The solar cell component is a realization of the double-diode PV substitute model, the developed form of which is shown in Formula (1) and (2). The form of this model is non-linear and \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Name of the PV Module Parameter:**} & **Standard Module** & **Half-Cell Module** \\  & **JAM60S01-320/PR** & **JAM60S03-320/PR** \\ \hline Type of PV cells & Monocrystalline Silicon & Monocrystalline Silicon \\ Number of PV cells/half-cells, (pcs.) & 60 & 120 \\ Maximum Power Point—\(P_{MPP}\), (W) & 320 & 320 \\ Open Circuit Voltage—\(U_{OC}\), (V) & 40.8 & 40.22 \\ Voltage in MPP—\(U_{MPP}\), (V) & 33.48 & 33.34 \\ Short Circuit Current—\(I_{SC}\), (A) & 10.05 & 10.16 \\ Current in MPP—\(I_{MPP}\), (A) & 9.56 & 9.6 \\ Module Efficiency—\(\eta\), (\%) & 19.6 & 19.2 \\ Temperature Coefficient of \(I_{SC}\)—\(\alpha_{T}\), (\%\({}^{\circ}\)C) & +0.06 & +0,051 \\ Temperature Coefficient of \(U_{OC}\)—\(P_{T}\), (\%\({}^{\circ}\)C) & \(-\)0.30 & \(-\)0.29 \\ Temperature Coefficient of \(P_{MPP}\)—\(\gamma_{T}\), (\%\({}^{\circ}\)C) & \(-\)0.38 & \(-\)0.36 \\ Temperature in NOCT conditions, (\({}^{\circ}\)C) & 45 & 45 \\ Dimensions of PV Module, (mm) & \(1650\times 991\times 35\) & \(1678\times 991\times 35\) \\ Mass, (kg) & 18.2 & 18.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of parameters of PV modules: standard and half-cell, provided by the manufacturer—in STC. Author’s elaboration based on producer data [9]. entangled, it can be solved only by means of simulation iterative calculations.