Determination of internal parasitic of photovoltaic polycrystalline silicon Hooray MCP-12 under direct sunlight using the Lambert-W function

The performance of photovoltaic modules (PV) to produce the electric energy is determined by parasitic internal resistance consisting of series and parallel resistance (R_s and R_sh). An increase in internal resistance implies a decrease in the quality of output analytically. In this research, we demonstrate the modeling of polycrystalline PV module, which is available in the market using the Lambert-W function and simple experiment by extracting the voltage current (I-V) parameters under dark current conditions by providing a screen in the module. This condition results in relatively small currents and voltages, in accordance with most regions in Indonesia, which have relatively less sunlight due to changing seasons, but are not in the repair of the PV module’s internal parasitic resistance. The I–V characteristic of PV was measured using normal irradiance at a temperature of 30°C for a short period of 5 minutes to preserve constant illumination. A maximum open circuit voltage V_oc of 16.9V and short circuit current I_sc of 0.93 A are denoted in the I-V curve while the maximum output power P_max is obtained for 14.08 V and 0.82 A. Using the Lambert-W function which is modified based on the ideal equation of solar cells in the PV module, the parasitic internal resistance R_s and R_sh are then calculated resulting in 1.5 Ω and 107.5 Ω respectively. This internal resistance obtained from this model shows an internal loss and decrease performance due to cell-to-cell contact with the PV module during its operation period.