锂离子电池组能量均衡时序优化及控制

发布时间：2018-06-09 22:58

本文选题：锂离子电池组 + 非线性PID算法　；参考：《重庆大学》2014年硕士论文

【摘要】：随着不可再生能源的大量消耗和环境污染程度日趋严重，新能源的开发利用已经迫在眉睫，混和动力电动车和纯电动车，光伏发电和风力发电设备遍布世界各个角落。锂离子电池具有比能量大、循环寿命长、自放电率低和无记忆效应等优点广泛应用为能量存储设备，成为了当前最具发展前景的动力电池。但是由于在串联锂离子电池组中的每单个电池的特征属性不能完全一致，在使用的过程中会存在能量不平衡情况造成电池组损坏。所以需要对串联电池组的能量进行均衡，以保证特征属性一致，延长电池的使用寿命。目前，国内外的专家已经提出了不少针对锂离子电池能量管理的控制策略，主要包括均衡电路和控制算法的设计。但就目前的研究情况来看，该控制系统还存在着很多的问题，均衡结构复杂难以实现、控制精度差、均衡效率低等。针对目前的研究情况，论文采用了一种针对无损均衡电路的非线性PID控制算法，并针对无损均衡网络结构，采用动态规划思想，设计了一种能量路径优化算法以提高均衡的效率，减少均衡时间和均衡过程中的能量损失。论文的主要工作如下： ①对无损均衡电路的电压电流进行了分析，根据能量传输途径和交换过程建立了系统的数学模型。 ②研究了目前已有的均衡控制算法，结合电池组模型，采用非线性PID控制算法对单个均衡电路进行了控制，解决了控制系统中控制精度不高、且稳态电压震荡等问题。 ③运用动态规划思想，提出了一种锂离子电池组均衡系统能量路径优化算法，对系统中的均衡顺序和能量流进行优化控制，使整个系统运行在最优状态下，减少能量损失，提高了均衡效率。 ④通过仿真对模糊控制算法、非线性PID算法进行了比对，分析各算法的优劣。搭建了10节锂离子电池组均衡控制系统实验平台，对提出的算法进行了实验验证，并取得了较好的实验效果。综上所述，论文针对目前锂离子电池组均衡控制系统的不足，提出了一种能够避免电流、电压振荡，提高均衡速度的均衡控制算法，，用于单个均衡电路的控制；并针对整个均衡系统的网络结构，运用动态规划思想，建立了一套锂离子电池组优化控制方法。通过对均衡路径的规划，实现了均衡系统的优化控制，提高了均衡效率和减少了均衡时间。通过仿真和实验证明了算法能有效的解决锂离子电池组能量均衡系统中的控制和优化问题，满足了系统的应用需求。
[Abstract]:With the large consumption of non-renewable energy and the increasingly serious environmental pollution, the development and utilization of new energy is imminent. Hybrid electric vehicles and pure electric vehicles, photovoltaic power generation and wind power generation equipment all over the world. Lithium-ion batteries have been widely used as energy storage devices with the advantages of large specific energy, long cycle life, low self-discharge rate and no memory effect, and have become the most promising power battery. However, because the characteristic attributes of each single cell in the series lithium ion battery are not completely consistent, there will be energy imbalance in the process of use, which will lead to battery damage. So it is necessary to equalize the energy of the series battery to ensure the consistency of the characteristic attributes and prolong the life of the battery. At present, experts at home and abroad have put forward many control strategies for energy management of lithium ion batteries, including the design of equalization circuit and control algorithm. However, according to the current research situation, there are still many problems in the control system, such as the complexity of the equilibrium structure is difficult to achieve, the control accuracy is poor, the balance efficiency is low, and so on. According to the current research situation, this paper adopts a nonlinear pid control algorithm for lossless equalization circuit, and adopts the idea of dynamic programming for lossless equalization network structure. An energy path optimization algorithm is designed to improve the equalization efficiency and reduce the equalization time and energy loss in the equalization process. The main work of this paper is as follows: 1 the voltage and current of the lossless equalization circuit are analyzed, and the mathematical model of the system is established according to the energy transmission path and the switching process. 2 the existing equalization control algorithms are studied, combined with the battery pack model. The nonlinear pid control algorithm is used to control a single equalization circuit, which solves the problems of low control precision and steady voltage oscillation in the control system. In this paper, an energy path optimization algorithm for lithium ion battery equalization system is proposed, which optimizes the equalization sequence and energy flow in the system, makes the whole system run in the optimal state and reduces the energy loss. The equalization efficiency is improved. 4 the comparison of fuzzy control algorithm and nonlinear pid algorithm is carried out through simulation, and the advantages and disadvantages of each algorithm are analyzed. The experimental platform of 10 lithium ion battery equalization control system is built, and the proposed algorithm is verified experimentally, and good experimental results are obtained. In summary, the thesis aims at the deficiency of the current lithium ion battery equalization control system. An equalization control algorithm which can avoid current and voltage oscillation and improve equalization speed is proposed, which can be used to control a single equalization circuit, and dynamic programming is applied to the network structure of the whole equalization system. A set of optimal control method for lithium ion battery was established. By programming the equilibrium path, the optimal control of the equalization system is realized, the equalization efficiency is improved and the equalization time is reduced. Simulation and experiments show that the algorithm can effectively solve the control and optimization problems in the Li-ion battery energy equalization system, and meet the application needs of the system.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM912

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