最小均方自适应滤波器设计及性能影响因素分析

Analysis on the Influence of Factors Performance and Design of Least Mean Square Adaptive Filter

同步相量测量单元是全局同步时钟下实现电网中电压和电流信号同步相量、频率和频率变化率测量的仪器,但信号中通常包括大量噪声,对其应用造成较大影响。本文在数字滤波器基础上提出最小均方自适应滤波器,阐述了最小均方自适应滤波器基本原理和计算方法,通过算例分析了步长参数、滤波器阶数、信噪比变化对最小均方自适应滤波器收敛速度、系统跟踪速度和稳态误差等指标的影响,揭示了其变化规律。

The synchronous phasor measurement unit is used to realize the synchronous phasor,frequency and frequency change rate of voltage and current signals in the power grid under the global synchronous clock,but the signals usually include a large amount of noise,which has a great impact on its application.In this paper,digital filters are introduced first,and then the least mean square adaptive filter is proposed.The basic principle of the least mean square adaptive filter is described.The influence of step size parameter,filter order and signal-to-noise ratio on the convergence speed,system tracking speed and steady-state error of the minimum mean square adaptive filter is analyzed through a calculating example,and its variation law is revealed,which plays an important role in processing the data collected by the synchronous phasor measurement unit.