混合动力系统的拓扑结构和控制策略决定了整车的性能．文中提出了一种适合城市公交工况的基于地面扭矩耦合方式的混联式液压混合动力系统，以及以满足车辆瞬时动力需求为基础、以全局经济性最优为目标的整车能量管理策略; 借鉴研究混杂系统的方法和思路，采用了分层递阶控制以简化系统的结构; 基于 Matlab/Simulink/Statflow 联合仿真技术，建立整车前向模型，并选择 ECE 城市循环工况对整车的经济性和动力性进行分析．结果表明，文中所提出的液压混合动力系统及控制策略可明显改善发动机的输出特性，有效地提高整车的燃油经济性和瞬时动力性．

The whole vehicle performance depends on the topological structure and the control strategy of hybridpower system.In this paper,a series- parallel hydraulic hybrid system is proposed on the basis of ground torquecoupling mode.This kind of hydraulic hybrid system is suitable for the working condition of urban public traffic.Inorder to meet the instantaneous power requirement of vehicles and achieve the optimal global economy,an energymanagement strategy is proposed for the whole vehicle.Then,to simplify the system structure,the progressivelyhierarchical control method is adopted according to the hybrid system theory.Finally,through the Matlab/Simu-link/Statflow co- simulation,a forward model of the whole vehicle is established and the fuel economy and thedynamic performance of a whole vehicle are analyzed under the ECE city driving cycle.The results show that theproposed system and strategy can significantly improve the engine output characteristic and effectively increase thefuel economy and the instantaneous dynamic performance of the whole vehicle.