【作者】 凌凯；

【导师】 邓亚东； 苏楚奇；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2011， 硕士

【摘要】 随着汽车车载电器和电子控制技术用电需求的逐步增加,42V电气系统是国际社会公认的解决汽车用电供需矛盾的下一代电气系统方案。在42V汽车电源的基础上,开发起动机/发电机一体化(ISG)的弱混合动力系统已成为混合动力汽车开发的热点。ISG型HEV的优势在于可以现有内燃机汽车为基础改造,开发成本低；ISG能使发动机快速起停的功能能避免发动机经常性的处于怠速工况,即使发动机停机时也能由电机单独驱动空调等电器附件；汽车在加速或爬坡等负荷较重的工况时电机能提供辅助动力；汽车减速或制动时利用电机的再生制动回收制动能量。在保持汽车动力性基本不变的前提下,这些独特的功能对改善汽车燃油经济性和降低排放有显著的功效。汽车尾气废热温差发电技术是利用热电材料的热电直接转换原理,将尾气的热量转化成可供汽车使用的电能。现阶段乘用车温差发电项目的实际转化效率不足5%,可获得的实际输出功率小于1KW。如何提高温差发电系统的输出功率和转化效率,使得温差发电装置能取代传统发电机为汽车电子设备供能或是以一定的混合度与发动机联合工作形成弱混合动力系统成为研究热点。本文结合ISG型42V HEV和温差发电系统的特点,提出了一种基于汽车尾气废热温差发电的ISG型42V HEV系统方案。在简要分析温差发电的基本原理、系统结构、系统的输入输出特性和42V动力系统基础理论、结构型式和功能模式的同时,针对构建的系统方案,以保证整车的动力性为前提,以降低燃油消耗和尾气排放为主要目标,进行温差发电系统的子系统构建和优化,以及42V动力传动系中发动机、ISG、蓄电池和变速器的选型和参数设计。基于MATLAB/Slmulink建模环境,以Advisor为平台,依据系统的结构、工作模式和控制策略,构建了温差发电系统的simulink模型,并将其作为一个子系统嵌入整车仿真模型之中,对其能量流动进行适当的控制；基于新系统的特点对advisor原有模型进行改进,建立传动系发动机、ISG、蓄电池、控制策略以及整车的仿真模型。利用建立的仿真模型,在Advisor中设置部件的仿真参数和加速、爬坡等性能要求,选择不同的循环工况进行仿真分析,对比分析了传统汽车、ISG型42V HEV和基于温差发电的ISG型42V动力系统的性能。在汽车动力性性能指标基本持平的情况下,汽车的燃油消耗和尾气排放得到了改善,由此可见,开发此新型动力系统对于提升整车的综合性能是行之有效的。更多还原

【Abstract】 As the demand for electricity of electric device and electronic control technology in the automobile gradually increases, today’s 12V car power supply system has become increasingly difficult to meet the demand for electricity of modern cars, the 42V car power supply is the next generation of vehicle electrical system program to solve the contradiction of automotive electricity supply and demand generally acknowledged by the international community.Based on the 42V power supply system, the development of mild hybrid vehicles characterized by integrated starter/generator(ISG) has become a hot spot. The advantages of mild hybrid vehicles based on ISG are below, it costs little to be modified based on the existing internal combustion engine vehicles, the ISG can make quick starts and stops of the engine to avoid engine idling in regular conditions, even if the engine shuts down,air conditioners and other electrical accessories can also be driven by the motor alone, the motor can provide auxiliary power when accelerating or hill climbing and other heavy load conditions,retrieve braking energy when deceleration or braking by the function of regenerative braking. These unique features have a significant effect to improve vehicle fuel economy and reduce emissions in the context of maintaining the same dynamic performance.The automobile exhaust waste heat thermoelectric power generation technology utilizes the principle of direct conversion for thermoelectric materials,converts the exhaust heat account for 40% of the chemical energy of fuel combustion to electricity used by vehicles. At the present stage, the actual conversion efficiency of power generation projects of the passenger vehicles is less than 5%, the actual output power available is less than 1KW. The methods of improving the output power and conversion efficiency for the thermoelectric power generation system.replacing the traditional generator by the thermoelectric generators for the electricity supply of the automotive or building a mild hybrid system to work together with a internal combustion engine by a certain degree of hybridization become a research hot spot.In this paper, it proposes a program of the ISG-type 42V HEV system based on the thermoelectric generation to combine the characteristics of the ISG-type 42V HEV system and the thermoelectric power generation system. After a brief analysis of the basic principles,system architecture and system features of thermoelectric generation and the basic theory, structure type and function realization mode of the 42V mild hybrid system, based on the system framework,it carries out the system construction and optimization of the subsystems for the thermoelectric generation,type selection and parameters design of the internal combustion engine, ISG, batteries and transmission in the 42V powertrain to ensure the same dynamic performance and aim at reducing fuel consumption and exhaust emissions.In order to find out the performance of this new power system, based on the MATLAB/Slmulink modeling environment and electric vehicle simulation software Advisor, depending on the system’s structure, work patterns and control strategies, it builds a simulink model of the thermoelectric power generation system,embeds it in the vehicle simulation model as a subsystem and carries a proper control of energy flow. On the basis of the existing models in the advisor, it improves the original models based on the characteristics of the new system,establishes the simulation models of the engine, ISG, batteries in the ISG-type 42V HEV powertrain, control strategy and the vehicle.Using the established simulation model, after setting the simulation parameters of parts, acceleration, climbing and other performance requirements in the Advisor, selectting some different driving cycles for simulation analysis, it carries a comparative analysis of the traditional car, ISG-type 42V HEV and the ISG-type 42V HEV based on thermoelectric generation. The fuel consumption and exhaust emissions have improved when vehicle dynamic performance remains the same, we can see, the development of this new power system for enhancing the vehicle’s overall performance is effective.更多还原