Pre-Arcing Characteristics of Different Rated Current Fuses in Parallel

Fuses are still widely used in power systems. However, the weak ability of low overload current disconnection restricts its application. To reduce the lower limit of the low overload interrupting capability of the fuse, this paper proposes a fuse design using different rated current fuses in parallel. In several times of experiments, the fuses with larger rated current are fused first, and then the current is broken by the fuses with smaller rated currents. This process has a higher current density on the fuses with a smaller rated current, which is helpful to the interrupting of overload fault. Compared with the traditional parallel design of the same fuse, the success rate of the parallel design of different rated current fuses is higher when the current is small. Finally, through the analysis of the I-t characteristic curve before the arc of the fuse, it is found that the uneven current distribution and I-t characteristic point movement are the reasons for the above experimental results.