Analysis of thermal behavior of power system fuse using finite element method

One of the most important protective devices in power system is fuses. It is important to know the thermal behavior of a fuse for an optimized design as well as for a right choice of the fuse rating with the aim to protect the power system. Passing the current from the fuse leads to hot the fuse element and open the current path and interrupt the fault current. So, the temperature of the fuse directly affects the fuse operation and melting. The designed fuse must operate correctly in the nominal and instantaneous over current (such as motor starting) and interrupt the short circuit current. In this paper, a 2D thermal model of fuse is developed in order to study the temperature distribution at a fuse in ANSYS. The effect of the current harmonics (current with different THD) on the fuse thermal is investigated and the temperature distribution through all fuse link elements is shown.