Thermal Analysis of the Fuse with Unequal Fuse Links Using Finite Element Method
In this paper a three dimensional thermal model of high breaking capacity fuse with unequal fuse links is proposed for both steady-state or transient conditions. The influence of ambient temperature and electric current on the temperature distribution inside the fuse, has been investigated. A thermal analysis of the unbalanced distribution of the electric current through the fuse elements and their influence on fuse link temperature rise, has been performed. To validate the three dimensional thermal model, some experimental tests have been done. There is a good correlation between experimental and simulation results. Keywords—Electric fuse, fuse links, temperature distribution, thermal analysis.
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.
A.C. short-circuit performance of notched fuse elements
The heating of notched fuse elements under a.c. short-circuit conditions has been studied, using finite-difference methods to solve for the transient current and temperature distributions in the element. The method gave good agreement with experimental results. A comparison of the behaviour with that of a uniform-section element described in a companion paper shows that there are significant differences. In particular, the notched element shows large discontinuities in the time/current characteristic, and a wide variation in prearcing I2t, depending on the circuit parameters.