RBF-AR (radial basis function network-based autoregressive) model is reconstructed as a new type of general radial basis function (RBF) neural network, which has additional linear output weight layer in comparison...RBF-AR (radial basis function network-based autoregressive) model is reconstructed as a new type of general radial basis function (RBF) neural network, which has additional linear output weight layer in comparison with the traditional three-layer RBF network. The extended Kalman filter (EKF) algorithm for RBF training has low filtering accuracy and divergence because of unknown prior knowledge, such as noise covariance and initial states. To overcome the drawback, the expectation maximization (EM) algorithm is used to estimate the covariance matrices of noises and the initial states. The proposed method, called the EM-EKF (expectation-maximization extended Kalman filter) algorithm, which combines the expectation maximization, extended Kalman filtering and smoothing process, is developed to estimate the parameters of the RBF-AR model, the initial conditions and the noise variances simultaneously. It is shown by the simulation tests that the EM-EKF method for the reconstructed RBF-AR network provides better results than structured nonlinear parameter optimization method (SNPOM) and the EKF, especially in low SNR (signal noise ratio). Moreover, the EM-EKF method can accurately estimate the noise variance. F test indicates there is significant difference between results obtained by the SNPOM and the EM-EKF.展开更多
高能动力电池是供配电系统的核心储能模块,针对高能动力电池的应用构建了二阶等效电路模型。在等效电路模型的基础上,提出联合递推最小二乘(Recursive Least Squares,RLS)法和扩展卡尔曼滤波(Extended Kalman Filter,EKF)的荷电状态(Sta...高能动力电池是供配电系统的核心储能模块,针对高能动力电池的应用构建了二阶等效电路模型。在等效电路模型的基础上,提出联合递推最小二乘(Recursive Least Squares,RLS)法和扩展卡尔曼滤波(Extended Kalman Filter,EKF)的荷电状态(Stage of Charge,SOC)算法,并在其基础上改进为基于温度补偿的联合RLS法和EKF融合的SOC算法。基于MATLAB软件,设计改进前和改进后联合算法的仿真验证程序,并对结果进行了比较分析。仿真结果表明,基于温度补偿的联合算法可实现当SOC处于(0.25,1)的区域内,相对误差基本小于5%,验证了所提出的建模方法和求解方法的有效性。展开更多
蓄电池荷电状态(state of charge,SOC)是电池管理系统最为重要的参数之一,由于飞机蓄电池工作环境恶劣复杂,具有较强的非线性,给蓄电池的在线SOC估计带来较大的困难。以提高复杂应力条件下飞机蓄电池在线SOC估计精度为目的,采用性能测...蓄电池荷电状态(state of charge,SOC)是电池管理系统最为重要的参数之一,由于飞机蓄电池工作环境恶劣复杂,具有较强的非线性,给蓄电池的在线SOC估计带来较大的困难。以提高复杂应力条件下飞机蓄电池在线SOC估计精度为目的,采用性能测试实验对蓄电池性能参数的温度、放电率特性进行研究,并提出递推最小二乘法与扩展卡尔曼滤波算法结合的改进EKF方法,实现蓄电池等效电路模型参数的在线辨识以及蓄电池在线SOC的估计。上述方法通过物理实验进行了验证,实验结果表明,改进后EKF方法的SOC估计误差小于0.5%,估计精度获得明显提高。展开更多
基金This work was supported by the National Natural Science Foundation of China (51507015, 61773402, 61540037, 71271215, 61233008, 51425701, 70921001, 51577014), the Natural Science Foundation of Hunan Province (2015JJ3008), the Key Laboratory of Renewable Energy Electric-Technology of Hunan Province (2014ZNDL002), and Hunan Province Science and Technology Program(2015NK3035).
摘要RBF-AR (radial basis function network-based autoregressive) model is reconstructed as a new type of general radial basis function (RBF) neural network, which has additional linear output weight layer in comparison with the traditional three-layer RBF network. The extended Kalman filter (EKF) algorithm for RBF training has low filtering accuracy and divergence because of unknown prior knowledge, such as noise covariance and initial states. To overcome the drawback, the expectation maximization (EM) algorithm is used to estimate the covariance matrices of noises and the initial states. The proposed method, called the EM-EKF (expectation-maximization extended Kalman filter) algorithm, which combines the expectation maximization, extended Kalman filtering and smoothing process, is developed to estimate the parameters of the RBF-AR model, the initial conditions and the noise variances simultaneously. It is shown by the simulation tests that the EM-EKF method for the reconstructed RBF-AR network provides better results than structured nonlinear parameter optimization method (SNPOM) and the EKF, especially in low SNR (signal noise ratio). Moreover, the EM-EKF method can accurately estimate the noise variance. F test indicates there is significant difference between results obtained by the SNPOM and the EM-EKF.
摘要高能动力电池是供配电系统的核心储能模块,针对高能动力电池的应用构建了二阶等效电路模型。在等效电路模型的基础上,提出联合递推最小二乘(Recursive Least Squares,RLS)法和扩展卡尔曼滤波(Extended Kalman Filter,EKF)的荷电状态(Stage of Charge,SOC)算法,并在其基础上改进为基于温度补偿的联合RLS法和EKF融合的SOC算法。基于MATLAB软件,设计改进前和改进后联合算法的仿真验证程序,并对结果进行了比较分析。仿真结果表明,基于温度补偿的联合算法可实现当SOC处于(0.25,1)的区域内,相对误差基本小于5%,验证了所提出的建模方法和求解方法的有效性。
摘要蓄电池荷电状态(state of charge,SOC)是电池管理系统最为重要的参数之一,由于飞机蓄电池工作环境恶劣复杂,具有较强的非线性,给蓄电池的在线SOC估计带来较大的困难。以提高复杂应力条件下飞机蓄电池在线SOC估计精度为目的,采用性能测试实验对蓄电池性能参数的温度、放电率特性进行研究,并提出递推最小二乘法与扩展卡尔曼滤波算法结合的改进EKF方法,实现蓄电池等效电路模型参数的在线辨识以及蓄电池在线SOC的估计。上述方法通过物理实验进行了验证,实验结果表明,改进后EKF方法的SOC估计误差小于0.5%,估计精度获得明显提高。