一种改进的自适应谐波电流检测方法

Improved Adaptive Harmonic Current Detection Method

针对现有的基于双曲正切函数变步长LMS(least mean square)算法的谐波电流检测仍存在稳态误差和收敛速度不能同时满足要求的问题,分析了一种基于双曲正切函数变步长LMS算法改进的变步长算法,利用误差的时间均值估计建立步长与误差之间的新型双曲正切函数关系以控制步长的更新,降低稳态误差,提高算法的检测精度。同时,对权值采用2次迭代更新,将2次迭代的结果作为新的权值,以加快权值的更新速度,提高算法的收敛速度。该算法具有较高的检测精度的同时还有较快的响应速度。Matlab/Simulink的仿真结果证明了该算法用于谐波电流检测具有很好的效果。

Aimed at the problem that the existing harmonic current detection based on the hyperbolic tangent function variable-step-size least mean square(LMS)algorithm still has steady-state errors and the convergence speed cannot me-et the requirements at the same time,an improved variable-step-size algorithm based on the hyperbolic tangent function variable-step-size LMS algorithm is analyzed.The time-averaged estimation of the error is used to establish a novel hyperbolic tangent function relation between the step size and the error so as to control the step size update,reduce the steady-state error,and improve the algorithm’s detection accuracy.Meanwhile,the weights are updated twice,and the results after two iterations are used as new weights to speed up the weights update and improve the algorithm’s convergence speed.As a result,the proposed algorithm has a higher detection accuracy and a faster response speed.The simulation results obtained using Matlab/Simulink show that this algorithm has a good effect on harmonic current detection.