基于SOC的储能电池组均衡策略研究

针对单体到单体(Cell to Cell)型均衡电路用于风光储能电池组均衡时能量转换效率低、均衡速度慢的问题,以电池组的SOC(State of Charge)一致为均衡目标,提出了一种基于电池模块化的均衡策略。该均衡策略以cuk电路作为底层均衡模块,以反激变换器作为顶层均衡模块,底层和顶层模块的控制相互独立,有效地提高了整体的能量转换效率和均衡速度。在MATLAB环境下,搭建了仿真模型,并与传统的cuk电路均衡策略进行了对比仿真分析,验证了所提均衡策略的有效性。     

基于SOC的串联电池组控流均衡控制策略

传统Cuk均衡控制策略能量转移效率低,为维持电池组SOC(State of Charge)一致,文章提出了一种新型控制策略,保证了电池组的控流均衡。根据电池组的能量分布,该均衡控制策略能够实现对均衡器开关、均衡电流方向和大小的控制,提高了整体的能量转移效率。利用Matlab进行模型仿真分析,仿真结果表明,均衡控制策略要比传统均衡控制策略更加有效。     

基于等效电路模型的动力电池SOC估计方法综述

动力电池的准确建模及荷电状态(State of charge,SOC)的精准估计对提高电池的利用效率、延长使用寿命具有重要意义.各类SOC估计方法中,基于电池等效电路模型估计法的精准性和鲁棒性好,且电池模型结构简单、计算量小,在电池管理系统(Batter management system,BMS)中具有较好应用前景....     

船用电池管理系统及SOC算法研究

依照中国船级社《纯电池动力船舶检验指南》(CCS GUIDANCE NOTES GD22-2019)要求,设计了一种船舶通用型电池管理系统.针对大容量电池系统电池荷电状态估算不准确问题,开发了一种扩展的卡尔曼滤波算法.经试验验证,所设计的电池管理系统能够满足船用要求;所采用的SOC算法能够较准确地估算出电池剩余电量.     

基于双向DC-DC变换器的串联电池组主动均衡电路

针对单体电池串联成组使用时出现不一致性的问题,提出了一种基于双向DC-DC变换器的串联电池组主动均衡电路。使用双向DC-DC变换器将单体电池中的高能量输送到能量低的单体电池中,无需额外的存储组件来存储和传送能量,减少了能量损失,提高了均衡效率。根据电池开路电压（open circuit voltage,OCV）与荷电状态（state of charge,SOC）之间近似分段线性的关系,采用以电压和SOC双变量作为均衡策略,通过相互实时修正电压均衡和SOC均衡,使得电池组间能量动态趋于一致。最后通过搭建由4节单体电池组成的均衡电路实验平台,对提出的均衡电路和均衡控制策略进行有效性验证。     

基于Cuk电路的多交错对称式均衡方案

均衡控制作为解决电动汽车电池组不一致性问题的有效方式,已发展成为汽车动力电池的关键技术之一.针对目前电感式拓扑均衡时间长、均衡速度慢的问题,本文提出了一种基于Cuk电路的多交错对称式均衡方案.以单体电池作为研究对象,引入中止参数,完成均衡策略的设计与优化,最终实现均衡控制.该均衡方案拓扑结构简单、均衡速度快,克服了传统...     

基于高斯过程回归的UKF锂离子电池SOC估计CSCD

高精度的电池荷电状态估计是电动汽车电池管理系统的关键技术之一,其估计精度直接影响能量管理效率和汽车的续航里程。传统的滤波方法基于模型来估计电池SOC,但难以建立锂离子电池精确的数学模型。针对此问题,提出一种基于高斯过程回归的无迹卡尔曼滤波(UKF)锂离子电池SOC估计方法,使用高斯过程回归在有限的训练数据下建立等效电路模型的测量方程,在UKF和高斯过程回归之间建立关联。该模型能够充分联合利用现有实验数据和被预测实时状态数据,实现SOC估计。结果表明,与传统UKF相比,基于高斯过程回归的UKF算法具有较高精确性。     

基于SOC均衡的分布式电池储能系统协同控制策略

研究分布式电池储能系统的优化控制方法以及电池荷电状态（SOC）均衡策略,提出基于SOC均衡的协同控制策略。利用多智能体系统（MAS）理论,实现电池储能系统的协同控制,并采用多智能体分布式算法,实现功率指令的自适应分配,进而实现SOC动态均衡。针对传统多智能体算法收敛速度较慢的问题,提出一种基于模型预测控制（MPC）的分布式算法,利用MPC对传统多智能体算法进行优化,提高收敛速度。最后利用实际储能功率数据进行仿真,验证了所提策略的有效性和算法在收敛速度上的优势。     

基于蒙特卡洛和SH-AUKF算法的锂电池SOC估计

针对锂离子电池荷电状态(State of charge,SOC)估计精度低的问题,将Sage-Husa自适应算法与无迹卡尔曼滤波算法相结合,提出了一种可以对系统噪声进行不断更新和修正的自适应滤波新算法——SH-AUKF算法。在动态应力测试(Dynamic stress test,DST)工况下,采用无迹卡尔曼滤波(Unscented Kalman filter,UKF)、自适应无迹卡尔曼滤波(Adaptive unscented Kalman filter,AUKF)和SH-AUKF三种算法分别对SOC进行估计。结果表明,SH-AUKF算法估计SOC的误差最小,估计精度最高。与UKF相比,SH-AUKF算法的估计精度提高了45.4%;与AUKF相比,SH-AUKF算法的估计精度提高了14.3%。为了进一步降低噪声干扰的偶然性和突发性对SOC估计的影响,在估计过程中加入了蒙特卡洛采样方法。结果表明,融合了蒙特卡洛方法的SH-AUKF算法估计SOC时,估计误差区间仅为±1×10^-3,有效提高了估计精度。     

Active equalization control strategy of Li-ion battery based on state of charge estimation of an electrochemical-thermal coupling model

Aiming at solving the problem of poor battery cell consistency caused by excessive decay of cell capacity or increased internal resistance during the operation of lithium-ion battery packs for vehicles, the paper proposes an active equalization control with 12-V power supply as an equalization energy source, which achieves efficient energy replenishment of individual cells with low power. The electrochemical-thermal coupling model of lithium-ion battery is built, and the order reduction of large-scale system theory ensures that the model had higher accuracy and lower amount of calculation, which is suitable for vehicle battery management system (BMS). Then the extended Kalman filter algorithm is used to calculate the real-time state of charge (SOC) of each cell and set as an equalization variable. The equalization simulation circuit is built with MATLAB/Simulink, the experimental platform of active equalization system for battery packs is constructed, and the battery packs are tested for equalization in static state. The simulation and experimental results show that the proposed active equalization control strategy can rapidly improve the voltage inconsistency between single cells, and the energy transfer efficiency can reach about 85% during the equalization process.     

Characterisation of charge and discharge behaviour of lithium ion batteries with olivine based cathode active material

This paper gives insight to the physical processes taking part during the two-phase transition in lithium intercalation compounds. The behaviour of olivine based electrodes is in the special focus of this work. These electrodes exhibit phase juxtaposition within the electrode particles over a wide state of charge (SOC) range. Measurements were made to explore effects related to the formation of distinct phase sequences within the particles. Asymmetric charge characteristics, a load history dependency of the internal resistance and a voltage effect related to the disappearance of certain phase regions (the later on called vanishing phase effect) were identified. Moreover, these measurements give evidence to the existence of stable phase regions inside the electrode active material. An intuitive model is given to visualize the phase regions within spherical olivine particles. Therefore an analytical approach is developed in order to take the geometry of the particles, the ion permeability as well as the size distribution of the particles in consideration. According to the developed approach and the obtained measurement results, an enhanced cell equivalent electrical circuit is evaluated, considering phase shell development effects.     

Robust polynomial approach for state of charge estimation in NiMH batteries

In this work we estimate the state of charge (SOC) of NiMH rechargeable batteries using a robust optimal filter based on a simplified electrochemical model. The robust filter guarantees that the supremum of the error variance - difference between real and estimated SOC - with respect to all admissible uncertainties be minimum. The results are compared with those obtained using the linear Kalman filter. We conclude that both estimations have similar performance, although the robust filter is easier to tune. Experimental results with commercial batteries are provided to illustrate the estimation procedure and it performance.     

基于UGOA-BP的锂电池SOC估算

电池荷电状态(SOC)的精确估算是储能设备安全运行的关键,本工作提出一种基于均匀分布策略改进的蝗虫优化算法和BP神经网络(UGOA-BP)的联合算法,在标准蝗虫优化算法(GOA)的基础上,引入了均匀分布函数,更新了非线性控制参数c,构建了新的随机调整机制,扩大了算法搜索范围,打破了局部开发受限的局面.同时,又受粒子群算...     

全固态锂电池界面的研究进展

与传统锂离子电池相比,基于无机固体电解质的全固态锂电池,具有安全性能高、循环寿命长、能量密度高等优点,是目前锂电池研究领域的热点之一,未来有望在电动汽车和智能电网等领域得到广泛应用。全固态锂电池中,电极与固体电解质之间的固固接触相比固液接触具有更高的界面接触电阻,同时,界面相容性和稳定性也显著影响全固态锂电池的循环性能和倍率性能。而在固体电解质中,晶界电阻决定了电解质整体的离子电导率,因此,界面问题是决定电池电化学性能的关键所在。本文重点综述了全固态锂电池中各种界面问题的研究现状,主要包括界面调控机理、修饰方法,并指出全固态锂电池中界面调控面临的挑战。     

基于注意力改进BiGRU的锂离子电池健康状态估计

锂离子电池的健康状态(state of health,SOH)是电池管理系统的核心问题,对其精确的评估能够保障电池的安全可靠运行.然而在实际应用中,容量较难直接测得,导致SOH估算困难.为了获得准确的SOH,本文提出一种基于注意力改进双向门控循环单元(BiGRU)的锂离子电池SOH估计方法.首先提取电池充放电曲线中的电压、电流与阻抗等参数,通过自编码器(auto encoder,AE)对其降维,提取特征量并减少数据间的冗余性.其次,引入注意力机制(attention mechanism,AM)对输入变量分配权重,突出对SOH估计起到关键作用的特征量.最后,利用BiGRU学习输入变量与容量之间的映射关系,捕获容量衰减下的长期依赖性.在不同充电倍率的电池数据集上的结果表明,该方法对不同类型电池的SOH皆可以实现高精度估计,均方根误差在1.1％以下.     

Support vector based battery state of charge estimator

This paper investigates the use of a support vector machine (SVM) to estimate the state-of-charge (SOC) of a large-scale lithium-ion-polymer (LiP) battery pack. The SOC of a battery cannot be measured directly and must be estimated from measurable battery parameters such as current and voltage. The coulomb counting SOC estimator has been used in many applications but it has many drawbacks [S. Piller, M. Perrin, Methods for state-of-charge determination and their application, J. Power Sources 96 (2001) 113–120]. The proposed SVM based solution not only removes the drawbacks of the coulomb counting SOC estimator but also produces accurate SOC estimates, using industry standard US06 [V.H. Johnson, A.A. Pesaran, T. Sack, Temperature-dependent battery models for high-power lithium-ion batteries, in: Presented at the 17th Annual Electric Vehicle Symposium Montreal, Canada, October 15–18, 2000. The paper is downloadable at website http://www.nrel.gov/docs/fy01osti/28716.pdf] aggressive driving cycle test procedures. The proposed SOC estimator extracts support vectors from a battery operation history then uses only these support vectors to estimate SOC, resulting in minimal computation load and suitable for real-time embedded system applications.     

Analysis of equalization technology of series lithium-ion battery pack based on power frequency modulation

近年来,锂离子电池在储能电站调频领域得到了飞速发展。为满足调频电站的电压和功率要求,需将大量电池单体进行串联,如此产生的电池组串联不一致性问题,以及调频过程中高倍率和频繁切换充放电状态对不一致性程度的加剧,严重影响电池组的使用寿命和安全性能。针对上述问题,本文基于调频储能串联锂离子电池模组不一致性问题的形成原因,归纳分析用于改善电池组串联不一致性问题的均衡技术和均衡策略。其中,均衡拓扑结构按能量流向角度进行分类梳理,均衡控制策略则基于均衡的不同目标进行优劣分析。在此基础上对锂离子调频电池模组均衡技术的发展趋势进行展望。     

固态锂二次电池关键材料中的空间电荷层效应:原理和展望

空间电荷层效应源于两相界面电化学势平衡的热力学要求,最初被用于解释复合离子导体中离子电导率的显著增大现象,后来在更多的体系中得到应用和发展,并且不但可以定性而且可以定量地解释多种离子的界面输运行为。特别是在纳米尺寸体系中,体相效应大大减小,界面空间电荷层效应更为显著的增加,利用这一效应不仅可以调控电导的大小,还可以设计构筑具有奇异特性的人工导体。目前,固态锂二次电池的研究受到关注,其中电解质/电极界面或复合电极内部界面可能存在的空间电荷层效应也引起越来越多的重视。本文首先基于两相界面的缺陷化学,从热力学基础角度讨论了空间电荷层产生的原理,评述了典型导电体系中存在的空间电荷层效应及其对宏观性能的影响。在此基础上,探讨了固态锂二次电池中的空间电荷层效应、有关的表征方法,以及利用空间电荷层提高电池性能的可能。     

An active balancer with rapid bidirectional charge shuttling and adaptive equalization current control for lithium-ion battery strings

This article proposes an active balancer, which features bidirectional charge shuttling and adaptive equalization current control, to fast counterbalance the state of charge (SOC) of cells in a lithium-ion battery (LIB) string. The power circuit consists of certain bidirectional buck-boost converters to transfer energy among the different cells back and forth. Owing to the characterization of the open-circuit voltage (OCV) vs SOC in LIB being relatively smooth near the SOC middle range, the SOC-inspected balance strategy can achieve more precise and efficient equilibrium than the voltage-based control. Accordingly, a compensated OCV-based SOC estimation is put forward to take into account the discrepancy of SOC estimation. Besides, the varied-duty-cycle (VDC) and curve-fitting modulation (CFM) methods are devised herein to tackle the problems of slow equalization rate and low balance efficacy, which arise from the diminution in balancing current as the SOC difference between the cells decreases in the later duration of equalization especially. The proposed strategies have taken the battery nonlinear characteristic and circuit parameter nonideality into account and can adaptively modulate the duty cycle with the SOC difference to keep balancing current constant throughout the balancing cycle. Simulated and experimental results are given to demonstrate the feasibility and effectiveness of the same prototype constructed. Compared with the fixed duty cycle and the VDC methods, the proposed CFM has the best balancing efficiency of 81.4%, and the balance time is shortened by 27.1% and 18.6%, respectively.