Helpful hints to enhance reliability of DC-DC converters in hybrid electric vehicle applications

This paper presents a new method for reliability assessment of bi-directional dc-dc converters which are used in electric and hybrid electric vehicles (EV/HEV). The proposed technique takes into account random modes of operation dictated by the driving scenarios. In order to consider the stochastic nature of the driving, Federal Test Procedure (FTP-75) driving cycle is selected as the reference. A bench mark bi-directional dc-dc converter circuit along with a Hybrid Energy Storage System (HESS) is selected as the typical HEV DC-DC converter. The new method for reliability assessment of HEV DC-DC converters under random behavior of driver is presented using Monte Carlo simulation and part stress method.