Integral power management strategy for a complex hybrid electric vehicle — catering for the failure of an individual component

Abstract

A fault-tolerant function is critical for ensuring sufficient reliability and performance availability of control units in hybrid electric vehicles. For the purpose of providing a fault-tolerant system, a systematic integral power management strategy for a complex hybrid electric vehicle is presented at a system level. Once a subsystem component failure occurred, the hybrid vehicle system controller can take effective actions to achieve an acceptable performance. For instance, when the engine or battery fails to work, a limp-home operation is expected. Operational characteristics under normal modes and failure modes are discussed and a combined rule-based control strategy is developed to manage the power flow. Vehicle simulation integrated with a control algorithm is constructed and carried out in MATLAB/Simulink/Stateflow. Performances under normal and abnormal conditions are evaluated respectively.