The driving range of electric vehicles (EVs) is still an important factor restricting their development. Although the rising battery energy density has reached a bottleneck, which is a key constraint, the drive energy management strategy also has a significant effect and can improve the driving range of EVs, since wheel traction torque control can directly optimize the driving energy consumption of EVs. In order to comprehensively analyze the current research status of driving energy management and clarify its development direction, this review focuses on the driving energy management strategy of EVs and systematically summarizes the configurations and power distribution strategies of the dual-motor coupling drive system (DCDS), as well as torque vectoring control strategies of the decentralized drive system. Firstly, driving energy losses are analyzed in detail, which mainly include electric loss, tire slip energy dissipation, and the power of cornering resistance. Secondly, typical configurations of the DCDS are introduced, and the power distribution strategies of the DCDS are comprehensively reviewed. Finally, as an interesting energy-saving technology, energy-saving torque vectoring, generally applied to decentralized drive systems, is reviewed in detail in terms of its energy-saving pathways and control strategies, which are classified as front-and-rear torque vectoring and left-and-right torque vectoring. Research findings indicate that the driving range of EVs can be effectively increased by applying a driving energy management strategy based on several novel multi-power source drive systems. The development of a driving energy management strategy and the required novel drive systems will be a valuable and crucial direction for further energy conservation in EVs.

X-by-wire skateboard chassis is one of the most attractive and prospective chassis architectures for future intelligent electric vehicles. Since the characteristics of the four-wheel regenerative brake torque and electromechanical friction brake torque of the four-wheel independent drive/brake electric vehicle (FWID/BEV) are all independently controllable, the coordinated distribution of the over-actuated four-wheel electric and mechanical hybrid braking torque has considerable potential to supply systematic improvement in recovery of braking energy than conventional vehicles. To further explore the potential of energy recovery and achieve better cross-system control, a framework of integrated optimal torque distribution control strategy (IOTD) is proposed for FWID/BEVs with electromechanical hybrid braking (EMHB) systems. Wherein, orientation estrangement among interaxis, interwheel, and intersystem torque distribution under multiple conditions is eliminated. Instead, the torque distribution process is highly integrated. Co-simulation verification results show clear improvement in terms of stability and economy. Hardware/Driver-in-the-Loop (HDiL) test results further show that the IOTD reaches up to about 3.32% more energy recovery rate with a reasonable computing load under combined braking conditions.

The development of energy-saving vehicles is an important measure to deal with environmental pollution and the energy crisis. On this basis, more accurate and efficient energy management strategies can further tap into the energy-saving potential and energy sustainability of vehicles. The equivalent consumption minimization strategy (ECMS) has shown the ability to provide a real-time sub-optimal fuel efficiency performance. However, when taking the different market prices of fuel and electricity cost as well as battery longevity cost into account, this method is not very accurate for total operational economic evaluation. So, as an improved scheme, the instantaneous cost minimization strategy is proposed, where a comprehensive cost function, including the market price of the electricity and fuel as well as the cost of battery aging, is applied as the optimization objective. Simulation results show that the proposed control strategy for series-parallel hybrid electric buses can reduce costs by 41.25% when compared with the conventional engine-driven bus. The approach also impressively improves cost performance over the rule-based strategy and the ECMS. As such, the proposed instantaneous cost minimization strategy is a better choice for hybrid electric vehicle economic evaluation than the other main sub-optimal strategies.