Coupled Electro-Thermo-Mechanical Analysis to Understand Fuse Element Ageing by Finite Element Method

This article discusses the ageing of electrical fuses and proposes a novel method for estimating the fuse's lifetime. Fuse ageing is primarily caused by repeated cyclic thermal loads under AC/DC currents. Temperature variations cause the development of thermo-mechanical stresses due to the geometric constraints in the fuse, resulting in damage that accumulates over time. As a result, fuses may blow after a series of current pulses with values that deviate from the original I-t curve. Because of the above, the lifetime estimation of the fuse is essential for improving the reliability of electrical systems. A coupled electro-thermo-mechanical methodology using finite element simulations has been proposed to predict fuse lifetime. For the given pulse current input, the evolution of Joule's heat, temperature, stress, strain, and lifetime prediction has been described. The present study's findings can be used to evaluate the phenomenon of fuse ageing and make recommendations for fuse replacement.