Crash safety of a power electronic unit of an electrified vehicle

Abstract

A HAZOP analysis and FMEA revealed safety-critical components of the power electronic unit (PEU) and potential hazard processes in case of mechanical crash loads. The mechanical crash loads acting on the PEU were derived for a PEU positioned in a reference vehicle. On that basis, a matrix of mechanical tests representing critical quasi-static and dynamic load cases with the aim to observe the onset of failure modes of the PEU was developed. The analysis of the PEU revealed the capacitor, electrical conductors and cooling plate as critical components with potentially hazardous behavior in case of failure. In the crush tests, the failure of the cooling plate and contact between electrical conductors were detected, but no hazardous behavior of the capacitor was observed. Moreover, suggestions are discussed on how to minimize the risks of hazards in case of failure.