Reliability Estimation of Wired and Wireless Fast Electric Vehicle Charging Systems

Power electronic components in fast electric vehicle charging systems (FEVCSs) are invariably subjected to high electrical stresses, compromising the reliability of the entire charging system. Therefore, to ensure a robust and cost-effective operation, reliability estimation must be considered as an integral aspect of the design process of FEVCSs. This article presents a comprehensive reliability analysis strategy, which is applicable for both wired and wireless FEVCSs. The proposed strategy estimates the reliability at component to system-level and analyzes the impact of rest periods on FEVCS reliability. This is achieved through two modeling steps, consisting of an electro-thermal model and a reliability estimation model. Experimental results are presented to validate the proposed strategy. The findings, based on a case study of two 80 kW wired and wireless FEVCSs, are presented to demonstrate how the lifetime and reliability of semiconductor switches, capacitors, and overall chargers are influenced by the fast charging conditions. The study also shows how the introduction of rest periods to the charging schedule will substantially influence the reliability of both wired and wireless FEVCSs.