Abstract:  As photovoltaic systems evolve towards higher voltages and smaller sizes, stringent requirements are imposed on core protection devices such as fuses. For the φ10×85mm miniaturized fuses required in photovoltaic equipment, they must simultaneously meet the core indicators of a 32A rated current, 1500VDC rated voltage, and a maximum 30kA breaking capacity. Traditional products, due to the limitations of their arc-extinguishing structure design, frequently experience arcing in high-voltage short-circuit scenarios, with prominent protection failure issues, making them unsuitable for the safe operation of photovoltaic inverters and other equipment. This paper focuses on the compatibility design goal of the traditional φ10×85mm external structure and conducts breakthrough research on high-voltage small-sized fuses. By introducing a composite structure of silicone gel, tin balls, and insulating ceramic spacers, a new arc-extinguishing system is constructed to optimize the arc-extinguishing path and energy absorption efficiency. Experimental verification shows that this optimized design effectively solves the arc-extinguishing problem in high-voltage small-volume scenarios, with the product's breaking capacity stably reaching 30kA, and the short-circuit fault response speed meeting the requirements of the IEC 60269-6 standard. The low I²t value feature significantly enhances the protection effect of downstream equipment. Currently, this fuse has been successfully applied in core equipment such as photovoltaic inverters and combiner boxes, providing a reliable solution for high-voltage safety protection in photovoltaic systems and demonstrating significant engineering application value and promotion prospects.
 

12th ICEFA call for paper