Fuse Modeling for Reliability Study of Power Electronic Circuits

This paper describes a comprehensive modeling approach on reliability of fuses used in power electronic circuits. When fuses are subjected to current pulses, cyclic temperature stress is introduced to the fuse element and will wear out the component. Furthermore, the fuse may be used in a large variation of ambient temperature, e.g. in deserts and the accumulated damage in the fuse elements is gradually increasing due to thermo-mechanical stress that results in resistance increase and further unexpected failures. Consequently, the electrical characteristics of the fuse like I2t, breaking capacity, and rated voltage/current are opposed to shift in time to effect early breaking during the normal operation of the circuit. Therefore, in such cases, a reliable protection required for the other circuit components will not be achieved. The thermo-mechanical models, fatigue analysis and thermo-electrical models of fuses are presented by FEM simulations in order to identify the important factors affecting the performance of fuses at different ambient temperatures and cycling operation.