Analysis and Experimental Verification of a Fault-Tolerant HEV Powertrain

This paper presents a fault-tolerant powertrain topology for series hybrid electric vehicles (SHEVs). The introduction of a redundant phase-leg that is shared by three converters in a standard SHEV powertrain allows us to maximize the reliability improvement with minimal part-count increase. Therefore, the cost increase is kept to minimum as well. The new topology features fast response in fault detection and isolation, and postfault operation at rated power throughput. Two implementations of the fault-tolerant design are presented in conjunction with elaborated discussion of the operating principles, control schemes, and fault diagnostic methods. The substantially improved reliability over standard SHEV powertrains is demonstrated by analysis of the Markov reliability model. Time-domain simulation based on a Saber model has been conducted and the results have verified the feasibility and performance of the proposed SHEV drive system. A scaled-down laboratory prototype has been built and the experimental results further validate the robust fault detection/isolation scheme and uncompromised postfault performance.