基于Dymola的电动车热管理系统模块化建模与集成仿真

发布时间：2018-06-02 15:04

本文选题：电动汽车 + 热管理系统　；参考：《吉林大学》2017年硕士论文

【摘要】：电动汽车作为一种节能环保的交通运输工具,近些年来受到了极大的关注和发展。现阶段电动汽车上所搭载的动力电池仍以锂离子化学电池为主,然而其能量效率和寿命受温度的影响非常严重:锂离子电池在低温下的能量效率极低,因此从节能的角度,应当为低温下的车载锂电池施加一定的加热措施;锂离子电池在高低温下都会面临严重的老化衰退,进而缩短电池的循环寿命,因此从降低电池替换成本的角度,也应当采取相应的温控措施。针对以上问题,本文以某纯电动客车项目为依托,设计了一套液体循环加热系统,以实现在冬天对电池的预热;以及一套双蒸发器空调制冷系统,以实现在夏天对电池和乘员舱的制冷。借助Dymola这一适于系统模块化建模和多领域集成仿真的软件平台,本文对以上两套热管理系统的部件进行了模块化划分,并分别搭建了各子模块的模型。之后将各子模块集成为Dymola下的热管理系统,在不同车辆行驶条件和热管理方案下,仿真分析了热管理系统的表现和电池性能会受到的影响。对预加热系统的仿真结果进行了对比,定性地得出了低温下电池预热需求的大小与环境温度和车辆续驶里程的关系;对于制冷系统,仿真对比了不同电池冷却方式的制冷效果。最后根据低温下对电池进行预热的实际项目需求,针对预加热系统,以整车运行成本最低为目标,定量地求解了不同环境温度和续驶里程下电池的最优预热目标温度,并进行了实车试验。本文的研究内容具体如下:(1)查阅国内外相关研究领域的论文著作,重点调研了锂离子电池的热电、衰退特性,热管理系统的研究现状和Dymola的应用现状,确定了本文的研究内容和侧重点。(2)在前人的研究基础上,分析各种热管理方式的利弊,选择液体为电池的热管理介质。针对低温下电池包的预热需求,提出一套液体循环加热系统方案;针对高温下动力电池和乘员舱的制冷需求,提出一套双蒸发器空调制冷系统方案。分析两个系统的拓扑结构和工作原理,并对关键部件进行匹配,确定建模时部件的相关参数。(3)在探究了Dymola建模机理的基础上,将整车热管理系统划分为五大子模块:动力电池、充电桩、液体循环加热、双蒸发器空调和乘员舱。对每个模块的工作原理进行研究,并依照Dymola的建模特点搭建模型。其中电池模块的搭建是依据本文提出的半经验电池热电-衰退动态耦合模型。(4)将动力电池、充电桩、液体循环加热模块集成为预加热系统,在给定的工况和环境下对此系统进行了对比仿真,从提升电池能量效率和减小容量衰退的角度,定性分析了不同条件下电池预热需求的大小,并得出了环境温度越低时预热需求应该越大,而续驶里程越长时预热需求不一定会越大的结论。将动力电池、空调系统、乘员舱模块集成为制冷系统,仿真研究了制冷系统的引入会对电池性能造成的影响,并对比了强制风冷、空调风冷、空调液冷这三种冷却方式对电池的制冷效果,结果表明空调液冷的制冷效果最好。(5)将整车运行成本量化为两部分:整车电能消耗成本和电池老化成本。然后根据项目需求,以整车运行成本最低为目标,在Dymola中求解了不同环境温度和续驶里程下电池的最优预热目标温度,即求解了不同条件下预加热系统应当将电池加热到何种温度。仿真结果表明,随着环境温度的降低或者续驶里程的缩短,电池的最优预热目标温度应该越大。另外,通过对仿真结果的分析,发现在低温条件下对电池进行预热会增加整车电能消耗成本,但是可以大幅降低电池老化成本。在两者的综合作用下,预热过程仍可以大幅降低整车运行成本。最后,在实车上布置了预加热系统,进行实车试验,验证了电池模型的精度和低温下对电池进行预热的必要性。
[Abstract]:Electric vehicles, as a kind of energy saving and environmental protection vehicle, have received great attention and development in recent years. The power cells on electric vehicles are still mainly lithium ion chemical batteries at the present stage. However, the energy efficiency and life of the electric vehicles are greatly influenced by the temperature. The energy efficiency of lithium ion batteries at low temperature is very low, because of the low energy efficiency of the lithium ion batteries. From the energy saving point of view, a certain heating measure should be applied to the lithium battery at low temperature. The lithium ion battery will face serious aging decline at high temperature and low temperature, and thus shorten the cycle life of the battery. Therefore, the temperature control measures should be taken from the angle of reducing the replacement cost of the battery. Based on the electric bus project, a set of liquid circulating heating system is designed to realize the preheating of the battery in the winter, and a double evaporator air conditioning refrigeration system to achieve the cooling of the battery and the crew module in the summer. With the help of Dymola, a software platform suitable for modular modeling and multi domain integrated simulation, the above paper The components of the two sets of heat management systems are divided into modules, and the models of each sub module are set up respectively. Then each sub module is integrated into a heat management system under Dymola. Under different vehicle driving conditions and heat management schemes, the performance of the heat management system and the performance of the electric pool will be influenced. The real results are compared, and the relationship between the size of the battery preheating demand at low temperature and the environment temperature and the driving mileage of the vehicle is qualitatively obtained. For the refrigeration system, the simulation results are compared with the different cooling methods of the battery. Finally, the pre heating system is carried out in accordance with the pre heating system and the whole vehicle is carried out according to the pre heating system. At the lowest cost, the optimal preheating target temperature of battery under different ambient temperature and driving mileage was quantitatively calculated and the actual vehicle test was carried out. The contents of this paper are as follows: (1) consult the paper works at home and abroad, and focus on the thermal power, decline characteristics and the research of the thermal management system. The present situation and the application status of Dymola have been determined. (2) on the basis of previous research, the advantages and disadvantages of various heat management methods are analyzed. Liquid is selected as the heat management medium for battery. A set of liquid circulating heating system is proposed for the preheating demand of battery pack at low temperature. A set of dual evaporator air conditioning refrigeration system scheme is proposed. The topology and working principle of the two systems are analyzed and the key components are matched to determine the relevant parameters of the components in the modeling. (3) on the basis of exploring the mechanism of Dymola modeling, the whole car heat management system is divided into five modules: power battery, Charging pile, liquid circulation heating, double evaporator air conditioning and crew module. The working principle of each module is studied, and the model is built according to the modeling characteristics of Dymola. The building of battery module is based on the semi empirical battery thermoelectric decay dynamic coupling model proposed in this paper. (4) power battery, charging pile, liquid circulating heating module. It is integrated into a preheating system to simulate the system under given conditions and environment. From the angle of improving the battery energy efficiency and reducing the capacity decline, the size of the preheating demand under different conditions is qualitatively analyzed. The higher the demand for preheating is needed when the environment temperature is lower, and the preheating demand is the longer the driving mileage is. The power cell, air conditioning system and the crew module are integrated into the refrigeration system. The effects of the introduction of the refrigeration system on the battery performance are studied, and the effect of the three cooling modes on the electric pool is compared with the forced air cooling, air conditioning and air conditioning. The results show that the cooling effect of the air conditioning liquid cooling is shown. (5) the total vehicle operation cost is quantified as two parts: the electric energy consumption cost and the battery aging cost. Then according to the project demand, the optimal preheating target temperature of the battery under the different ambient temperature and the driving mileage is solved in the Dymola, that is, the pre heating system under different conditions should be solved. The simulation results show that the optimal preheating target temperature of the battery should be greater with the decrease of the ambient temperature or the shorter driving mileage. In addition, through the analysis of the simulation results, it is found that the preheating of the battery at low temperature will increase the cost of the electric energy consumption, but the battery can be greatly reduced. Under the combination of the two, the preheating process can still greatly reduce the cost of the whole vehicle. Finally, the pre heating system is arranged on the real car, and the real car test is carried out. The precision of the battery model and the necessity of preheating the battery at low temperature are verified.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U469.72

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