增程式电动汽车功率分流与运行优化方法研究

Range extended electric vehicle (REEV) can overcome the shortcomings of the pure electric vehicle effectively (short driving range and long charging time), thus developing REEV has important implications for achieving the upgrading of China’s automobile industry and strategic transformation of powertrain electrification. When the REEV power train is in range extended mode, the power flow is complicated, efficiency factors are diversified and the range extender is mechanical decoupling from the driving system. Based on these features, the main research contents of this project are as follows: 1) Reveal the factors which affect the energy loss and lifetime decay of the battery as well as fuel consumption and emissions of the range extender, then construct the total operating efficiency model; 2) Analyze the influence of the transient high-frequency component of the vehicle power flow on the total operating efficiency of the vehicle, and then explore the optimal power splitting between the range extender and power battery by using the wavelet analysis method; 3) Construct the range extender fuel consumption and emissions multi-objective optimization model in which the engine speed and generator torque are selected as the optimization variables and the fuel-electricity efficiency, HC, CO and NOx emissions are consider as the optimization objectives, and then the intelligent multi-objective optimization approach is utilized to achieve the multi-objective optimization of the fuel consumption and emissions. Through the implementation of this project, new theory and method on vehicle power flow splitting and operating optimization will be proposed, the research result will provide theoretical support for the development of the electric vehicle energy management strategy.

增程式电动汽车可以有效克服纯电动汽车续驶里程短、充电时间长的缺点，对于我国汽车产业结构升级和动力系统电动化战略转型具有重要意义。围绕增程模式下车辆动力系统所呈现出的功率流向复杂化、效率影响因素多元化和增程器机械解耦特性，项目重点研究：1)揭示影响动力电池能量损耗、寿命衰减以及增程器油耗和排放的各项因素，建立整车综合效率模型；2)分析整车功率需求中高频暂态分量对整车综合运行效率的影响，并采用小波分析方法探索增程器和动力电池之间的最优功率分流策略；3)以发动机转速和发电机转矩为寻优变量，以增程器油-电转换效率、HC、CO和NOx排放为优化目标，建立增程器多目标优化模型，采用多目标智能优化算法实现增程器油耗和排放的多目标优化。项目将提出增程式电动汽车功率分流和运行优化新方法，改善车辆的综合运行效率，研究成果将为电动汽车能量管理提供新的理论和方法支撑。

围绕研究内容，项目主要开展了以下四个方面的研究：.（1）提出了“单体解耦-分散式控制器串联”主动均衡控制系统拓扑结构，通过在放电过程中实时调整分散式控制器母线电压调节系数α及均衡加速系数β，在保证母线电压稳定的前提下，实现了单体放电速率与SOC偏差的线性比例动态调节。.（2）提出了电动汽车混合储能多工况三端口DC/DC变换器结构，该拓扑结构集成能量型储能装置端口、功率型储能装置端口及负载端口，可实现任意两个电气端口之间能量双向变换。设计了电压闭环控制器和电流闭环控制器，构建了小波功率分流方法，在保证母线电压稳定的前提下，实现了输出功率在功率型储能装置和能量型储能装置之间的精确分配。.（3）综合考虑增程器的油-电转换效率特性、HC排放特性、CO排放特性以及NOx排放特性，构造了增程器油耗和排放的多目标优化模型，同时结合实际增程器操作中的机械和电气约束特征，给出了多目标优化模型的转速、转矩约束条件，采用基于模糊优先性的多目标粒子群算法对模型进行了求解，得出了增程器系统的最优全局工作点和各功率条件下的多目标最优工作曲线。.（4）综合功率器件导通特性分析、死区时间分析、信号处理转换时间分析、A/D转换时间分析、调制度/载波周期分析以及零点漂移误差扩大效应分析，实现最小采样时间的精确定量计算，开发出低THD、高电流重构精度，能够在低调制度、高载波频率下运行的全工况单电流传感器电机控制系统。.所开发的电动汽车功率分流控制器可将锂离子动力电池高频功率需求分量频率降至原始值的1/16、峰值输出功率降低 20%；所提出的电驱动系统单传感器电流重构误差低于2%、相电流高次谐波含量低于3%、三相电流畸变率低于1.6%。.项目共发表学术论文10篇(其中SCI/EI收录论文5篇，中科院一区论文2篇、《中国电机工程学报》、《电工技术学报》等EI论文3篇)；累计申请国家发明专利16项，授权5项；培养硕士研究生4名。