Changes in the characteristics of silicon photovoltaic cells of solar arrays after current overloads

Recently, much attention has been paid to the study of the influence of current overloads and local overheating on the degradation of the electrical characteristics of the photovoltaic components of solar arrays. First of all, it is connected with the tasks of increasing the reliability and durability of the operation of such renewable sources of electrical energy. Such studies are of particular interest due to the recent emergence of new methods and devices for improving the reliability of solar arrays by isolating inactive (defective or shaded) areas of their photovoltaic components (photovoltaic cells and photovoltaic modules). This paper presents the research results on the influence of current overloads on the current-voltage and volt-watt characteristics and the electrical parameters of photovoltaic cells of solar arrays based on monocrystalline silicon. The testing was performed using the cyclic current overload mode, which is the flow of electric breakdown current passed through the back-turned diode of a photovoltaic cell for several seconds. After that, the photovoltaic cell was cooled to room temperature, and then its current-voltage and volt-watt characteristics were measured. The degradation (decrease) of all the basic electrical parameters of photovoltaic cells (open-circuit voltage, short-circuit current, filling factor of the current-voltage characteristic, and maximum power) has been established. The additive nature of the changes and the average relative decrease of the indicated electrical parameters for one breakdown cycle are determined. Comparison of the response time range of the PolySwitch fuses with the breakdown durations of photovoltaic cells is performed. The conclusion is drawn about the prospect of using such resettable fuses as protection in emergency situations that are associated with current overloads in solar arrays.