Novel energy management strategy for a dual-motor hybrid electric vehicle considering frequency of mode transitions

• Novel penalty mechanisms to avoid frequent mode transition. • The balance between drive comfort and fuel economy achieved. • Mode transition stability-conscious energy management strategy designed and tested. The plug-in hybrid electric vehicles (PHEV) can alter powertrain operating mode in different driving conditions, its energy management strategy (EMS) is priority issue to be considered to improve fuel economy, however, due to the multi-mode configuration and complex powertrain architecture, most of the EMS tend to switch the operating mode frequently, its influence on vehicle drivability and driving comfort are usually ignored, to tickle this issue, a novel EMS considering mode transitions constraints (EMS-MTC) is proposed in this research. Two penalty functions are designed to deal with unwanted mode transitions, then they are incorporated into the optimization process of EMS algorithm, a tradeoff between fuel economy and frequency of mode transition is realized via genetic algorithm, the Hardware-in-the-loop (HiL) tests with UDDS and CLTC-P cycles indicate that more than 60% of mode transitions in adaptive equivalent consumption minimization strategy (A-ECMS) can be reduced in EMS-MTC, at the price of slight increase (about 2%) of fuel consumption, which proves its potential for practical application.