As lithium-ion batteries become increasingly prevalent in electric scooters,vehicles,mobile devices,and energy storage systems,accurate estimation of remaining battery capacity is crucial for optimizing system perform...As lithium-ion batteries become increasingly prevalent in electric scooters,vehicles,mobile devices,and energy storage systems,accurate estimation of remaining battery capacity is crucial for optimizing system performance and reliability.Unlike traditional methods that rely on static alternating internal resistance(SAIR)measurements in an open-circuit state,this study presents a real-time state of charge(SOC)estimation method combining dynamic alternating internal resistance(DAIR)with artificial neural networks(ANN).The system simultaneously measures electrochemical impedance various frequencies,discharge C-rate,and battery surface temperature during the∣Z∣atdischarge process,using these parameters for ANN training.The ANN,leveraging its superior nonlinear system modeling capabilities,effectively captures the complex nonlinear relationships between AC impedance and SOC through iterative training.Compared to other machine learning approaches,the proposed ANN features a simpler architecture and lower computational overhead,making it more suitable for integration into battery management system(BMS)microcontrollers.In tests conducted with Samsung batteries using lithium cobalt oxide cathode material,the method achieved an overall average error of merely 0.42%in self-validation,with mean absolute errors(MAE)for individual SOCs not exceeding 1%.Secondary validation demonstrated an overall average error of 1.24%,with MAE for individual SOCs below 2.5%.This integrated DAIR-ANN approach not only provides enhanced estimation accuracy but also simplifies computational requirements,offering a more effective solution for battery management in practical applications.展开更多
A modular multilevel converter(MMC)integrated with split battery cells(BIMMCs)is proposed for the battery management system(BMS)and motor drive system.In order to reduce the switching losses,the state of charge(SOC)ba...A modular multilevel converter(MMC)integrated with split battery cells(BIMMCs)is proposed for the battery management system(BMS)and motor drive system.In order to reduce the switching losses,the state of charge(SOC)balancing strategy with a reduced switching-frequency(RSF)is proposed in this paper.The proposed RSF algorithm not only reduces the switching losses,but also features good balancing performance both in the unbalanced and balanced initial states.The results are verified by extensive simulations in MATLAB/Simulink surroundings.展开更多
A fuzzy model was established to estimate the state of charge（SOC） of a lithium-ion battery for electric vehicles.The robust Gustafson-Kessel（GK） clustering algorithm based on clustering validity indices was appli...A fuzzy model was established to estimate the state of charge（SOC） of a lithium-ion battery for electric vehicles.The robust Gustafson-Kessel（GK） clustering algorithm based on clustering validity indices was applied to identify the structure and antecedent parameters of the model.The least squares algorithm was utilized to determine the consequent parameters.Validation results show that this model can provide accurate SOC estimation for the lithium-ion battery and satisfy the requirement for practical electric vehicle applications.展开更多
This paper presents a more accurate battery state of charge(SOC)and state of health(SOH)estimation method.A lithium battery is represented by a nonlinear two-order resistance-capacitance equivalent circuit model.The m...This paper presents a more accurate battery state of charge(SOC)and state of health(SOH)estimation method.A lithium battery is represented by a nonlinear two-order resistance-capacitance equivalent circuit model.The model parameters are estimated by searching least square error optimization algorithm.Precisely defined by this method,the model parameters allow to accurately determine the capacity of the battery,which in turn allows to specify the SOC prediction value used as a basis for the SOH value.Application of the extended Kalman filter(EKF)removes the need of prior known initial SOC,and applying the fuzzy logic helps to eliminate the measurement and process noise.Simulation results obtained during the urban dynamometer driving schedule(UDDS)test show that the maximum error in estimation of the battery SOC is 0.66%.Battery capacity is estimate by offline updated Kalman filter,and then SOH will be predicted.The maximum error in estimation of the battery capacity is 1.55%.展开更多
In order to improve the accuracy of the battery state of charge（SOC） estimation, in this paper we take a lithiumion battery as an example to study the adaptive Kalman filter based SOC estimation algorithm. Firstly, ...In order to improve the accuracy of the battery state of charge（SOC） estimation, in this paper we take a lithiumion battery as an example to study the adaptive Kalman filter based SOC estimation algorithm. Firstly, the second-order battery system model is introduced. Meanwhile, the temperature and charge rate are introduced into the model. Then, the temperature and the charge rate are adopted to estimate the battery SOC, with the help of the parameters of an adaptive Kalman filter based estimation algorithm model. Afterwards, it is verified by the numerical simulation that in the ideal case, the accuracy of SOC estimation can be enhanced by adding two elements, namely, the temperature and charge rate.Finally, the actual road conditions are simulated with ADVISOR, and the simulation results show that the proposed method improves the accuracy of battery SOC estimation under actual road conditions. Thus, its application scope in engineering is greatly expanded.展开更多
Battery management systems (BMS) must estimate the state-of-charge (SOC) of the battery accurately to prolong its lifetime and ensure a reliable operation. Since batteries have a wide range of applications, the SOC es...Battery management systems (BMS) must estimate the state-of-charge (SOC) of the battery accurately to prolong its lifetime and ensure a reliable operation. Since batteries have a wide range of applications, the SOC estimation requirements and methods vary from an application to another. This paper compares two SOC estimation methods, namely extended Kalman filters (EKF) and artificial neural networks (ANN). EKF is a nonlinear optimal estimator that is used to estimate the inner state of a nonlinear dynamic system using a state-space model. On the other hand, ANN is a mathematical model that consists of interconnected artificial neurons inspired by biological neural networks and is used to predict the output of a dynamic system based on some historical data of that system. A pulse-discharge test was performed on a commercial lithium-ion (Li-ion) battery cell in order to collect data to evaluate those methods. Results are presented and compared.展开更多
电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU-EKF的改进SOC估算算法...电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU-EKF的改进SOC估算算法。首先使用二阶RC电池等效模型,利用复合脉冲功率特性测试(HPPC)进行电池参数辨识;随后对电池模型进行状态空间方程的建立,并利用EKF算法进行更新迭代来估算电池的SOC,可以得到卡尔曼增益与SOC估算误差;最后将2个量结合HPPC工况下的电压与电流作为3DGRU网络的输入,真实的SOC作为输出来训练神经网络。实验结果表明,提出的3DGRUEKF算法估算SOC的均方根误差(RMSE)与平均绝对误差(MAE)均小于0.5%,具有良好的效果。展开更多
考虑电池单体老化差异所致的电池组不一致性,针对串联电池组荷电状态(state of charge,SOC)、容量估计问题,提出一种基于自回归等效电路模型(autoregression equivalent circuit model,AR-ECM)的平均差异模型(mean-difference model,MDM...考虑电池单体老化差异所致的电池组不一致性,针对串联电池组荷电状态(state of charge,SOC)、容量估计问题,提出一种基于自回归等效电路模型(autoregression equivalent circuit model,AR-ECM)的平均差异模型(mean-difference model,MDM)。基于此模型,提出串联电池组SOC、容量多尺度联合估计算法。该算法由2个部分组成,一是基于AR-ECM的MDM及差异化模型参数辨识策略:条件辨识策略和定频分组辨识策略;二是基于多时间尺度H无穷滤波(multi-timescale H infinity filter,Mts-HIF)的电池组SOC、容量联合估计算法。通过将所提出MDM中的自回归平均模型(autoregression mean model,AR-MM)与传统MDM中的n阶RC平均模型(nRC mean model,nRC-MM)比较,结果表明所提出的AR-MM在复杂运行工况下具有更优的动态跟随性能。依据最小化信息量准则(akaike information criterion,AIC),AR-MM具有更优的复杂度与精度的权衡。通过与基于多时间尺度扩展卡尔曼滤波(multi-timescale extended Kalman filter,Mts-EKF)联合状态估计算法比较,结果表明所提出的Mts-HIF状态估计算法具有更优的鲁棒性、精度和收敛速度。展开更多
文摘As lithium-ion batteries become increasingly prevalent in electric scooters,vehicles,mobile devices,and energy storage systems,accurate estimation of remaining battery capacity is crucial for optimizing system performance and reliability.Unlike traditional methods that rely on static alternating internal resistance(SAIR)measurements in an open-circuit state,this study presents a real-time state of charge(SOC)estimation method combining dynamic alternating internal resistance(DAIR)with artificial neural networks(ANN).The system simultaneously measures electrochemical impedance various frequencies,discharge C-rate,and battery surface temperature during the∣Z∣atdischarge process,using these parameters for ANN training.The ANN,leveraging its superior nonlinear system modeling capabilities,effectively captures the complex nonlinear relationships between AC impedance and SOC through iterative training.Compared to other machine learning approaches,the proposed ANN features a simpler architecture and lower computational overhead,making it more suitable for integration into battery management system(BMS)microcontrollers.In tests conducted with Samsung batteries using lithium cobalt oxide cathode material,the method achieved an overall average error of merely 0.42%in self-validation,with mean absolute errors(MAE)for individual SOCs not exceeding 1%.Secondary validation demonstrated an overall average error of 1.24%,with MAE for individual SOCs below 2.5%.This integrated DAIR-ANN approach not only provides enhanced estimation accuracy but also simplifies computational requirements,offering a more effective solution for battery management in practical applications.
文摘A modular multilevel converter(MMC)integrated with split battery cells(BIMMCs)is proposed for the battery management system(BMS)and motor drive system.In order to reduce the switching losses,the state of charge(SOC)balancing strategy with a reduced switching-frequency(RSF)is proposed in this paper.The proposed RSF algorithm not only reduces the switching losses,but also features good balancing performance both in the unbalanced and balanced initial states.The results are verified by extensive simulations in MATLAB/Simulink surroundings.
基金Sponsored by the National High Technology Research and Development Program of China("863"Program)(2003AA501800)
文摘A fuzzy model was established to estimate the state of charge（SOC） of a lithium-ion battery for electric vehicles.The robust Gustafson-Kessel（GK） clustering algorithm based on clustering validity indices was applied to identify the structure and antecedent parameters of the model.The least squares algorithm was utilized to determine the consequent parameters.Validation results show that this model can provide accurate SOC estimation for the lithium-ion battery and satisfy the requirement for practical electric vehicle applications.
基金Open Fund Project of State Key Laboratory of Large Electric Transmission Systems and Equipment Technology(No.SKLLDJ042017005)。
文摘This paper presents a more accurate battery state of charge(SOC)and state of health(SOH)estimation method.A lithium battery is represented by a nonlinear two-order resistance-capacitance equivalent circuit model.The model parameters are estimated by searching least square error optimization algorithm.Precisely defined by this method,the model parameters allow to accurately determine the capacity of the battery,which in turn allows to specify the SOC prediction value used as a basis for the SOH value.Application of the extended Kalman filter(EKF)removes the need of prior known initial SOC,and applying the fuzzy logic helps to eliminate the measurement and process noise.Simulation results obtained during the urban dynamometer driving schedule(UDDS)test show that the maximum error in estimation of the battery SOC is 0.66%.Battery capacity is estimate by offline updated Kalman filter,and then SOH will be predicted.The maximum error in estimation of the battery capacity is 1.55%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61004048 and 61201010)
文摘In order to improve the accuracy of the battery state of charge（SOC） estimation, in this paper we take a lithiumion battery as an example to study the adaptive Kalman filter based SOC estimation algorithm. Firstly, the second-order battery system model is introduced. Meanwhile, the temperature and charge rate are introduced into the model. Then, the temperature and the charge rate are adopted to estimate the battery SOC, with the help of the parameters of an adaptive Kalman filter based estimation algorithm model. Afterwards, it is verified by the numerical simulation that in the ideal case, the accuracy of SOC estimation can be enhanced by adding two elements, namely, the temperature and charge rate.Finally, the actual road conditions are simulated with ADVISOR, and the simulation results show that the proposed method improves the accuracy of battery SOC estimation under actual road conditions. Thus, its application scope in engineering is greatly expanded.
文摘Battery management systems (BMS) must estimate the state-of-charge (SOC) of the battery accurately to prolong its lifetime and ensure a reliable operation. Since batteries have a wide range of applications, the SOC estimation requirements and methods vary from an application to another. This paper compares two SOC estimation methods, namely extended Kalman filters (EKF) and artificial neural networks (ANN). EKF is a nonlinear optimal estimator that is used to estimate the inner state of a nonlinear dynamic system using a state-space model. On the other hand, ANN is a mathematical model that consists of interconnected artificial neurons inspired by biological neural networks and is used to predict the output of a dynamic system based on some historical data of that system. A pulse-discharge test was performed on a commercial lithium-ion (Li-ion) battery cell in order to collect data to evaluate those methods. Results are presented and compared.
文摘电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU-EKF的改进SOC估算算法。首先使用二阶RC电池等效模型,利用复合脉冲功率特性测试(HPPC)进行电池参数辨识;随后对电池模型进行状态空间方程的建立,并利用EKF算法进行更新迭代来估算电池的SOC,可以得到卡尔曼增益与SOC估算误差;最后将2个量结合HPPC工况下的电压与电流作为3DGRU网络的输入,真实的SOC作为输出来训练神经网络。实验结果表明,提出的3DGRUEKF算法估算SOC的均方根误差(RMSE)与平均绝对误差(MAE)均小于0.5%,具有良好的效果。
文摘考虑电池单体老化差异所致的电池组不一致性,针对串联电池组荷电状态(state of charge,SOC)、容量估计问题,提出一种基于自回归等效电路模型(autoregression equivalent circuit model,AR-ECM)的平均差异模型(mean-difference model,MDM)。基于此模型,提出串联电池组SOC、容量多尺度联合估计算法。该算法由2个部分组成,一是基于AR-ECM的MDM及差异化模型参数辨识策略:条件辨识策略和定频分组辨识策略;二是基于多时间尺度H无穷滤波(multi-timescale H infinity filter,Mts-HIF)的电池组SOC、容量联合估计算法。通过将所提出MDM中的自回归平均模型(autoregression mean model,AR-MM)与传统MDM中的n阶RC平均模型(nRC mean model,nRC-MM)比较,结果表明所提出的AR-MM在复杂运行工况下具有更优的动态跟随性能。依据最小化信息量准则(akaike information criterion,AIC),AR-MM具有更优的复杂度与精度的权衡。通过与基于多时间尺度扩展卡尔曼滤波(multi-timescale extended Kalman filter,Mts-EKF)联合状态估计算法比较,结果表明所提出的Mts-HIF状态估计算法具有更优的鲁棒性、精度和收敛速度。
