一种快速软件频率跟踪法

使用傅里叶级数基波的实部和虚部2个同方向变化的过零点之间的时间差测量信号频率存在跟踪速度较慢的问题，针对此，在推导傅里叶级数基波实部和基波虚部的表达式、分析得出基波实部导数的过零点与基波虚部的过零点一样的性质的基础上，提出利用基波实部和基波虚部乘积的导数作为输入信号，通过该输入信号相邻2个过零点之间的时间差求取信号频率的测频算法。理论分析得出该方法能够在1／4周期内跟踪出信号频率；仿真分析表明该方法能够较快地跟踪信号的频率，跟踪精度较高。

A Fast Software Frequency Tracking Method

Aiming at slow tracking of signal frequency of time difference measurement between crossover points changing in the same direction in real part and imaginary part of fundamental wave of Flourier series,the paper suggests using derivative of multiplied real part by imaginary part as input signal by time difference of the consecutive crossover points the signal frequency is measured on the basis of expression deduction of real part and imaginary part of Flourier series and analysis that crossover points of both real part and imaginary part of fundamental wave are naturally the same.It is concluded through theoretical analysis that the method can track signal frequency in 1/4 period.The simulation analysis shows that the method can efficiently track signal frequency and acquire higher accuracy.