Emulation of photovoltaic arrays under non-uniform environmental conditions

Purpose The purpose of this manuscript is to present a method for emulating photovoltaic (PV) arrays under non-uniform environmental conditions such as illumination, temperature and soiling using a programmable power supply. Design/methodology/approach A key element of the emulation method is generating the characteristics of the PV arrays, which is enabled by the software tool developed for this purpose. The software tool inputs are the connected PV modules’ current-voltage (I-V) characteristics, obtained through simulation or measurement and the connection topology. The outputs are a PV array’s I-V and corresponding power-voltage (P-V) characteristics. Findings The P-V characteristics of PV arrays under non-uniform environmental conditions have multiple local maxima. The operation and performance of maximum power point tracking (MPPT) algorithms are evaluated using such characteristics generated with the software tool, showing that multiple local maxima can mislead the MPPT algorithm. Output current distortion during the MPPT process is also measured, revealing changes in the output current spectrum. Practical implications Experimental evaluation of the performance of PV systems under non-uniform conditions is very difficult. Climatic conditions cannot be directly influenced, and creating an artificial environment that mimics certain conditions is complicated and expensive. Moreover, changing the array configuration for each experiment is time-consuming. The described method for emulating the PV array significantly facilitates the testing of PV systems and allows experiments in different scenarios that are not feasible in real conditions. Originality/value This manuscript describes a unique software tool for generating I-V characteristics for emulating PV arrays. The manuscript’s value is reflected in the method’s applicability and versatility.