混合动力客车模式切换多控制器的协调控制

Mode transition coordination control of hybrid electric bus based on multiple controllers

分析了并联混合动力客车由纯电动驱动模式向发动机单独驱动模式切换的过程,借鉴了切换系统的基本思想,提出混合动力客车模式切换多控制器的协调控制策略;按照离合器的状态将驱动模式切换过程划分为3阶段,根据车辆运行所处的不同阶段,设计了Fuzzy-PI控制器与滑模控制器对发动机与驱动电机进行动力协调控制;以冲击度作为评价模式切换品质的量化指标,在MATLAB/Simulink/Stateflow中建立了并联混合动力系统仿真模型,搭建了整车试验平台,分析了协调控制的效果。仿真结果表明:未采用协调控制策略时,在离合器滑摩阶段,由于离合器两端转速差较大,其传递摩擦转矩会产生约189N·m的扰动,导致车速骤降,反向的最大冲击度约为41.2m·s^(-3);采用协调控制策略后,在整个模式切换过程中冲击度变化范围为-3~4m·s^(-3),保证了动力传动系统输出的平稳性,有效地抑制了驱动模式切换过程中对车辆所造成的冲击;在一完整的驱动模式切换中,实际车速的偏差小于5%,冲击度控制在-5~7m·s^(-3),试验结果与仿真结果基本一致,证明了该策略的可行性与有效性。

The switching process from pure electric driving mode to engine driving mode of parallel hybrid electric bus was analyzed, the basic idea of switching system was considered, and the mode transition coordination control strategy of hybrid electric bus based on multiple controllers was proposed. The driving mode transition was divided into three phases in terms of clutch states. According to the vehicle operating status, fuzzy-PI controller and sliding mode controller were constructed to coordinate the engine and driving electric motor in the phases. The shock degree was used as quantitative index to assess the quality of mode transition. The simulation model of parallel hybrid electric bus was built in MATLAB/Simulink/Stateflow platform. The vehicle experiment platform was constructed, and the coordinated control effect was analyzed. Simulation result shows that when the coordinated control strategy is not adopted, the friction torque of clutch in slipping stage generates a reverse impact of 189 N ·m due to the large speed difference between the two sides of clutch, which results in the sharp decline of vehicle velocity and the maximum reverse shock degree of 41.2 m · s-3. When the coordinatedcontrol strategy is used, the variation of shock degree is --3-4 m · s-2 in entire mode transition. So the output stability of power transmission system is assured, and the impact caused by the switching of driving mode is restrained effectively. In an entire driving mode transition, the experiment result is basically consistent with the simulation result, the error of vehicle velocity is less than 5%, and the variation of shock degree is -5-7 m · s-3, so the strategy is feasible and effective. 1 tab, 13 figs, 26 refs.