【作者】 程龙；

【导师】 宋大凤；

【作者基本信息】 吉林大学 ， 机械（专业学位）， 2024， 硕士

【摘要】 电动汽车被公认为是减少交通运输部门对环境污染和化石燃料依赖的最有效途径,其发展一直受到续航里程这一瓶颈的限制;在电池能量密度提高有限的条件下,优化整车驱动构型、降低驱动损耗是缓解这个瓶颈的有效途径。双电机耦合驱动系统(Dual Motor Coupling Powertrain,DMCP)因其相比于传统单电机驱动系统具有更高的电机驱动负荷率和灵活的模式选择,在提高整车经济性、动力性和模式切换质量方面具有更大潜力。因此,本文在双电机耦合驱动系统类型的分析基础上选择适合于纯电动公交客车的双电机转矩耦合驱动系统,对其工作模式进行划分并分析各个工作模式对于提升电机工作效率的优势以及模式转换的边界条件和动力流动过程;而后从完整的双电机耦合驱动纯电动公交客车整车建模出发,重点研究双电机耦合驱动系统的能量管理以及模式切换控制策略。本论文主要工作内容如下:(1)双电机耦合驱动系统工作模式分析与建模。分析了本文研究对象双电机耦合驱动系统的构型优势以及机械特点,划分了工作模式及其适用工况,并详细分析了工作模式间的切换过程;以前向仿真的建模思路在Matlab/Simulink平台上建立了包括驾驶员模型、电机模型、动力电池模型、四挡AMT变速箱模型、主减速器模型以及汽车纵向动力学模型在内的双电机耦合驱动系统模型,为后文能量管理策略的优化设计、模式切换过程的控制策略及其主要阶段的优化控制研究奠定了基础。(2)DMCP模式切换及控制策略研究。对于纯电动汽车,针对其单一能源特性设计基于瞬时效率最优的能量管理策略,并将当前工作模式的最优电机等效效率结合优先因子来减少模式切换次数,通过合理的优先因子选取可以使得DMCP在增加少量电量消耗的情况下极大的减少模式切换次数;针对模式切换的控制问题,根据该驱动系统中各驱动模式的动力传递路线,划分出3种常用模式切换类型,分别为:单电机-单电机模式切换、双电机-单电机模式切换、双电机-双电机模式切换;对于驱动系统在电机转矩卸载以及恢复阶段对于双电机转矩协调变化的需求,设计了转矩协调控制策略;并对转速同步阶段设计电机主动同步控制策略;通过3种常用模式切换过程无动力中断模式切换控制策略与传统无动力补偿的控制策略的结果进行对比,证明无动力中断模式切换控制策略的有效性和优越性。(3)基于最优控制原理的转速同步过程研究。针对模式切换过程中重要阶段转速同步阶段,通过动力学分析建立考虑扭转振动特性的双电机耦合驱动系统动力学模型并详细分析了传统定值作为转速同步目标值不再合理的原因,提出使用另一电机转速估算变速箱输出轴转速的方法并对可行性进行仿真验证。最后应用最优控制原理对转速同步过程进行优化控制,并与增量式PID控制进行对比验证了所提算法的优越性。更多还原

【Abstract】 Electric vehicles are recognized as the most effective way to reduce environmental pollution and fossil fuel dependence in the transportation sector,and their development has been limited by the bottleneck of range;Under the condition that the energy density of the battery is limited,it is an effective way to alleviate this bottleneck by optimizing the drive configuration of the whole vehicle and reducing the drive loss.The Dual Motor Coupling Powertrain(DMCP)has greater potential to improve the economy,dynamics and mode switching quality of the whole vehicle due to its higher motor drive load rate and flexible mode selection compared with the traditional single-motor drive system.Therefore,based on the analysis of the types of dual-motor coupled drive system,this paper selects a dual-motor torque coupled drive system suitable for pure electric buses,divides its working modes,and analyzes the advantages of each working mode to improve the efficiency of the motor,as well as the boundary conditions and power flow process of mode conversion.Then,starting from the complete dual-motor coupling drive pure electric bus modeling,the energy management and mode switching control strategy of the dual-motor coupling drive system are studied.The main contents of this paper are as follows:(1)Analysis and modeling of the working mode of the dual-motor coupled drive system.The configuration advantages and mechanical characteristics of the dual-motor coupled drive system are analyzed,the working modes and their applicable working conditions are divided,and the switching process between the working modes is analyzed in detail.Based on the modeling idea of forward simulation,a dual-motor coupled drive system model including driver model,motor model,power battery model,four-speed AMT gearbox model,final drive model and vehicle longitudinal dynamics model is established on the Matlab/Simulink platform,which lays a foundation for the optimal design of energy management strategy,the control strategy of mode switching process and the optimal control of its main stages.(2)Research on DMCP mode switching and control strategy.For pure electric vehicles,an energy management strategy based on instantaneous efficiency optimization is designed for its single energy characteristic,and the optimal motor equivalent efficiency of the current working mode is combined with the priority factor to reduce the number of mode switches,and the DMCP can greatly reduce the number of mode switches with a small amount of power consumption through reasonable priority factor selection.Aiming at the control problem of mode switching,according to the power transmission route of each drive mode in the drive system,three common mode switching processes are divided,namely: single motor-single motor mode switching,dual motor-single motor mode switching,and dual motor-dual motor mode switching;In order to meet the requirements of the torque coordination of the two motors in the torque unloading and recovery stages of the drive system,a torque transfer control strategy was designed.The active synchronous control strategy of the motor was designed in the speed synchronization stage.The effectiveness and superiority of the non-dynamic interrupt control strategy are proved by comparing the results of the coordinated control strategy of non-dynamic interrupt mode switching in three common modes switching process with the control strategy of traditional non-dynamic compensation.(3)Research on speed synchronization process based on optimal control principle.Aiming at the speed synchronization stage,which is an important stage in the process of mode switching,a dynamic model of the dual-motor coupled drive system considering the torsional vibration characteristics is established through dynamic analysis,and the reason why the traditional fixed value is no longer reasonable as the target value of speed synchronization is analyzed in detail,and a method of estimating the output shaft speed of the gearbox using the speed of another motor is proposed,and the feasibility is verified by simulation.Finally,the optimal control principle is used to optimize the speed synchronization process,and the superiority of the proposed algorithm is proved by comparing with the incremental PID control.更多还原