Reliability evaluation of plug-in hybrid electric vehicle chargers

In this paper a framework is developed to analyze and evaluate the reliability of plug-in hybrid electric vehicle (PHEV) chargers. The general infrastructure of PHEV battery chargers is discussed and a two-phase interleaved unidirectional charger topology is selected as an example for reliability analysis. The design is fault-tolerant so that the controller is capable of fault detection, isolation, and reconfiguration with perfect coverage. Component level reliability is calculated using MIL-HDBK-217. A Markov model is proposed to analyze the reliability of the fault tolerant two-phase interleaved charger topology including the impact of repair. Reliability indices such as mean time to failure (MTTF) and mean time to first failure (MTTFF) are calculated. The proposed framework can be extended to reliability evaluation and comparison of all types of PHEV chargers and can help understand and improve future charging infrastructure designs.