车辆电液混合动力传动系统研究

发布时间：2018-10-07 21:00

【摘要】：面对我国汽车工业发展迅速和环境污染问题日益突出的相互矛盾,零排放、无污染的纯电动汽车引起了我国政府的重视。开发以纯电动汽车为代表的新能源汽车成为汽车行业发展的重要方向。而在新能源汽车研究中,再生制动技术又是其关键技术之一。然而纯电动汽车刚开始再生制动以及驱动时,电机会产生很大的冲击电流,如果该电流直接输入蓄电池,会对蓄电池寿命造成很大影响。为解决电池大电流充放电对其寿命的影响问题,通常采用复合储能系统。电池-超级电容复合储能系统中超级电容具有功率密度高、充放电时间短等优点,但是其内阻小、电池不容易管理,且存在与电池参数匹配困难,安全性差,成本高等问题。电池-液压复合储能系统中液压系统和电池之间没有电连接,安全性高,且液压系统也具有超级电容相当的优点,而且成本低、技术成熟。本文以长安志翔原型车为应用对象,在系统地研究了纯电动汽车制动过程以及复合储能系统基础上,设计了一种车辆新型电液混合动力传动系统,并进行了参数匹配设计、再生制动控制策略制定、系统综合建模以及联合仿真分析。论文主要研究工作如下:(1)分析了不同结构形式的车辆电液混合动力传动系统的特点,确定适用于本文研究的整车传动系统结构方案,并设计了液压系统控制回路方案。然后利用基于循环工况的参数匹配方法对整个动力传动系统关键部件进行了参数匹配设计,包括电机、蓄电池、液压泵/马达(二次元件)、蓄能器以及变速器等。(2)对整车制动时的动力学以及车轮动力学进行分析,为了在满足制动安全性条件下最大程度回收制动能量,根据制动法规以及动力学条件确定了前、后轴制动力分配、制动强度门限值以及制动模式判断策略,并在此条件下制定了大、小强度制动力分配策略以及基于Fuzzy-PID的ABS防抱死控制策略。(3)利用Matlab/simulink软件数学建模方面的优势,建立了整车模型、电机模型、电池模型、控制系统模型、耦合机构模型以及轮胎路面模型;利用AMEsim在硬件建模方面的优点,建立了摩擦制动系统模型以及液压再生制动系统模型,在此基础上,通过AMEsim-simulink联合仿真平台对系统的可行性进行分析。(4)首先分析了液压再生制动系统在驱动和制动状态下的动态响应以及效率;其次分析了液压调节单元在正弦激励下的动态响应;最后在不同的路面附着系数以及制动强度条件下,在所建立的联合仿真模型基础上对所提出的控制策略进行仿真分析。本文进行了车辆电液混合动力传动系统的设计以及参数匹配,提出了针对电液混合动力系统的再生制动控制策略,使液压系统和蓄电池系统良好的协调配合,既能避免动力电池大电流充放电对寿命的影响问题,又能增加纯电动汽车续驶里程,为纯电动汽车再生制动系统的设计提供了一种新思路,具有较好的应用前景。
[Abstract]:In the face of the contradiction between the rapid development of China's automobile industry and environmental pollution, the pure electric vehicle (EV) with zero emission and no pollution has attracted the attention of our government. The development of new energy vehicles represented by pure electric vehicles (EV) has become an important direction of automobile industry. In the research of new energy vehicle, regenerative braking technology is one of the key technologies. However, when the pure electric vehicle starts to regenerate braking and drive, the motor will produce a very large impulse current. If the current is fed directly into the battery, it will have a great impact on the battery life. In order to solve the problem of high current charge and discharge of battery, composite energy storage system is usually used. The super capacitor has the advantages of high power density, short charge and discharge time, but its internal resistance is small, the battery is not easy to manage, and it is difficult to match the battery parameters, the security is poor, and the cost is high. There is no electrical connection between the hydraulic system and the battery in the battery hydraulic composite energy storage system, and the hydraulic system has the advantages of super capacitance, low cost and mature technology. Based on the research of braking process and compound energy storage system of pure electric vehicle, a new type of electro-hydraulic hybrid power transmission system is designed in this paper, and the parameter matching design is carried out. The control strategy of regenerative braking is formulated, the integrated modeling of the system and the joint simulation are analyzed. The main work of this paper is as follows: (1) the characteristics of the vehicle electro-hydraulic hybrid drive system with different structure are analyzed, the structure scheme of the whole vehicle transmission system suitable for this paper is determined, and the hydraulic system control loop scheme is designed. Then the parameter matching design of the key parts of the whole power transmission system is carried out by using the parameter matching method based on the cycle working condition, including the motor, the battery, Hydraulic pump / motor (quadratic element parts), accumulator and transmission, etc. (2) the dynamics of braking and wheel dynamics of the whole vehicle are analyzed, in order to maximize the recovery of braking energy under the condition of satisfying the braking safety, According to the braking regulations and dynamic conditions, the braking force distribution of front and rear axle, the threshold value of braking strength and the judging strategy of braking mode are determined. Small strength braking force distribution strategy and ABS anti-lock braking control strategy based on Fuzzy-PID. (3) based on the advantages of mathematical modeling of Matlab/simulink software, the vehicle model, motor model, battery model, control system model are established. Based on the advantages of AMEsim in hardware modeling, the friction braking system model and the hydraulic regenerative braking system model are established. The feasibility of the system is analyzed on the AMEsim-simulink platform. (4) the dynamic response and efficiency of the hydraulic regenerative braking system under the driving and braking conditions are analyzed, and the dynamic response of the hydraulic regulating unit under sinusoidal excitation is analyzed. Finally, under the condition of different road adhesion coefficient and braking strength, the proposed control strategy is simulated and analyzed on the basis of the established joint simulation model. In this paper, the design and parameter matching of vehicle electro-hydraulic hybrid drive system are carried out, and the regenerative braking control strategy for electro-hydraulic hybrid power system is put forward, which makes the hydraulic system and battery system coordinate well. It can not only avoid the influence of high current charge and discharge on the life of power battery, but also increase the driving range of pure electric vehicle. It provides a new idea for the design of regenerative braking system of pure electric vehicle and has a good application prospect.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.2

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