Simulating Thermal Characteristics of an Electric Vehicle Fuse Using Multiphysics Based on Finite Element Method 2019-26-0233

Circuit protection fuses are an integral part in electric powertrain based automobiles such as Hybrid electric vehicles (HEVs)/Plug-in hybrid vehicles (PHEVs)/Battery electric vehicle (BEVs) to protect the components under overcurrent situations. This paper describes the transient thermal characteristics of fuses used in such electric vehicles where thermal cycling related failures are of great concern. A robust and accurate three-dimensional multiphysics model has been developed for obtaining temperature response in fuse element by solving the electric potential equation and thermal diffusion equation. Experiments were also performed to validate the model within 5 degree Celsius accuracy for various operating currents and thermocouple locations. Using the validated model, a representative duty cycle relevant to electric vehicle was simulated to understand the thermal behavior. Various operating parameters and their effect on thermal performance is also discussed. The described findings and simulation methodology would enable the fuse design engineers to incorporate various thermal management strategies at product and system level considering the thermal cycling effects.