摘要
分析了传统定步长最小均方(LMS)算法用于谐波电流检测的不足,采用一种新的变步长LMS自适应算法检测谐波电流:根据误差信号e(n)和e(n-D)的自相关估计调整步长迭代,当权系数远离最佳权值时,通过增大步长加快对时变系统的跟踪速度;当权系数接近最佳权值时,减小步长获得较小的稳态误差。通过递推公式参数的选择,可对系统的收敛速度与稳态失调进行更灵活的控制。推导出了该方法的理论表达公式,其增加的计算量很小,容易实现。该方法能有效调节步长,不受谐波电流的干扰。仿真结果证明了该谐波电流检测方法的有效性。
Based on the study of disadvantages of conventional fixed step-size LMS（Least Mean Square） algorithm for harmonic current detection,an adaptive LMS algorithm with variable step-size is provided,which adjusts the step-size according to the autocorrelation estimation between e（n） and e（n-D）. When the weight is far away from the optimal value,it increases the step-size to accelerate the tracking of time-variable system,while when the weight is near the optimal value,it decreases the step- size to minish the steady state error. By selecting appropriate parameters,the algorithm allows more flexible control of misadjustment and faster convergence speed. Its theoretical approximate expressions are derived. It is easy to be implemented with little additional calculation. The algorithm can effectively adjust the step- size while maintaining the immunity against harmonic current disturbance. Simulation results illustrate its effectiveness.
出处
《电力自动化设备》
EI
CSCD
北大核心
2006年第9期23-26,共4页
Electric Power Automation Equipment
关键词
谐波检测
自适应滤波
变步长
harmonic detection
adaptive filtering
variable step-size
