频率估计的ANF误差函数分析及稳态性能比较

Analysis of Error Functions and Comparison of Steady-state Performances for ANF Frequency Estimation

针对正弦信号进行自适应频率估计时,现有的自适应陷波器(ANF)存在精度不高、收敛速度慢和鲁棒性差的问题,首先,以ANF所采用的不同误差函数为对象,分析了不同情况下ANF误差函数在整个频率范围内的梯度值,讨论了频率靠近频谱两端(0或π)时的误差函数梯度值,明确了误差函数梯度值对ANF频率估计精度的影响;其次,对基于不同误差函数的ANF在稳态条件下的频率估计精度进行了分析,列出了不同ANF频率估计方法的优缺点,讨论了不同参数对ANF频率估计精度的影响;最后,针对不同的ANF频率估计方法进行了应用验证,为进一步提升ANF频率估计精度提供了参考。

According to the adaptive frequency estimation of sinusoidal signal,the existing adaptive notch filter(ANF)fre-quency estimation methods have the problems of low precision, slow convergence speed and poor robustness. Firstly, the error func-tions which widely adopted in ANF are considered as objectives. The gradients of different ANF error functions in the whole frequen-cy range under different conditions are analyzed. The discussions especially focus on the gradients of ANF error functions when sig-nal frequency is close to 0 or π, meanwhile, the influences of the gradient of the error function on the accuracy of ANF frequency es-timation are defined. Secondly, the frequency estimation accuracy of ANF based on different error functions is analyzed, and the ad-vantages and disadvantages of different ANF frequency estimation methods are listed. The influence of different parameters on ANFfrequency estimation accuracy is discussed. Finally, the application of ANF frequency estimation method is validated, which pro-vides a reference for further improving ANF frequency estimation accuracy.