This paper presents an approach that is useful for the identification of a fuzzy model in SISO system. The initial values of cluster centers are identified by the Hough transformation, which considers the linearity an...This paper presents an approach that is useful for the identification of a fuzzy model in SISO system. The initial values of cluster centers are identified by the Hough transformation, which considers the linearity and continuity of given input-output data, respectively. For the premise parts parameters identification, we use fuzzy-C-means clustering method. The consequent parameters are identified based on recursive least square. This method not only makes approximation more accurate, but also let computation be simpler and the procedure is realized more easily. Finally, it is shown that this method is useful for the identification of a fuzzy model by simulation.展开更多
分布式光伏、电动汽车的大规模接入加剧了低压配电网(low-voltage distribution network,LVDN)的三相不平衡,这种三相不平衡会产生中性线电流并导致电压波动等问题,造成三相线路的阻抗辨识问题无法简化至潮流统一的3个相同单相网络中进...分布式光伏、电动汽车的大规模接入加剧了低压配电网(low-voltage distribution network,LVDN)的三相不平衡,这种三相不平衡会产生中性线电流并导致电压波动等问题,造成三相线路的阻抗辨识问题无法简化至潮流统一的3个相同单相网络中进行独立求解。针对中性线不平衡电流的存在,根据子节点电压相关性原理,提出一套基于层级解构与分相递归策略的线路阻抗辨识方法。首先,通过层级解构划分配变层、分支层和用户层,建立层内节点关联子网络;其次,构建相线电压匹配模型,回溯分支层各相线阻抗,利用节点功率校验模型,实现配变层节点相位角估计;再次,根据电气矢量关系递推中性线参数,通过消除递推误差得到线路阻抗辨识结果;最后,通过实际系统与负荷数据验证该方法的有效性和准确性。展开更多
为了实现永磁同步直线电机PMSLM(permanent magnet synchronous linear motor)高精度的多电气参数在线辨识,提出了一种基于双模型的递推最小二乘电气参数在线辨识算法。首先,根据电机的dq轴电压方程分别建立了辨识定子电阻、永磁体磁链...为了实现永磁同步直线电机PMSLM(permanent magnet synchronous linear motor)高精度的多电气参数在线辨识,提出了一种基于双模型的递推最小二乘电气参数在线辨识算法。首先,根据电机的dq轴电压方程分别建立了辨识定子电阻、永磁体磁链的模型1和辨识q轴电感、d轴电感的模型2,并将2个辨识模型循环结合。其次,基于上述双模型结构,采用递推最小二乘算法实现电气参数在线辨识,并针对PMSLM运行时存在大量动态过程的特性,提出一种具有饱和特性的分段变遗忘因子;然后,对功率开关非理想因素导致的误差电压进行补偿,进一步提高了辨识的精准度;最后,仿真和实验结果证明了该辨识算法的有效性,且具有收敛速度快、辨识结果精度高、多工况适用等优点。展开更多
基金This project was supported by the Natural Science Foundation of Heilongjiang province and Doctor Foundation of Yanshan U-niversity.
文摘This paper presents an approach that is useful for the identification of a fuzzy model in SISO system. The initial values of cluster centers are identified by the Hough transformation, which considers the linearity and continuity of given input-output data, respectively. For the premise parts parameters identification, we use fuzzy-C-means clustering method. The consequent parameters are identified based on recursive least square. This method not only makes approximation more accurate, but also let computation be simpler and the procedure is realized more easily. Finally, it is shown that this method is useful for the identification of a fuzzy model by simulation.
文摘分布式光伏、电动汽车的大规模接入加剧了低压配电网(low-voltage distribution network,LVDN)的三相不平衡,这种三相不平衡会产生中性线电流并导致电压波动等问题,造成三相线路的阻抗辨识问题无法简化至潮流统一的3个相同单相网络中进行独立求解。针对中性线不平衡电流的存在,根据子节点电压相关性原理,提出一套基于层级解构与分相递归策略的线路阻抗辨识方法。首先,通过层级解构划分配变层、分支层和用户层,建立层内节点关联子网络;其次,构建相线电压匹配模型,回溯分支层各相线阻抗,利用节点功率校验模型,实现配变层节点相位角估计;再次,根据电气矢量关系递推中性线参数,通过消除递推误差得到线路阻抗辨识结果;最后,通过实际系统与负荷数据验证该方法的有效性和准确性。
文摘为了实现永磁同步直线电机PMSLM(permanent magnet synchronous linear motor)高精度的多电气参数在线辨识,提出了一种基于双模型的递推最小二乘电气参数在线辨识算法。首先,根据电机的dq轴电压方程分别建立了辨识定子电阻、永磁体磁链的模型1和辨识q轴电感、d轴电感的模型2,并将2个辨识模型循环结合。其次,基于上述双模型结构,采用递推最小二乘算法实现电气参数在线辨识,并针对PMSLM运行时存在大量动态过程的特性,提出一种具有饱和特性的分段变遗忘因子;然后,对功率开关非理想因素导致的误差电压进行补偿,进一步提高了辨识的精准度;最后,仿真和实验结果证明了该辨识算法的有效性,且具有收敛速度快、辨识结果精度高、多工况适用等优点。
