为寻求一种频率无关的实时相量计算方法，通过分析传统算法，提出一种可变数据窗正弦相量插值计算方法。该算法通过等间隔采样获得信号一个周期左右的样本数据，采样数据计算出信号的基波频率并确定信号的一个基频周期所需的最大采样点数N，计算信号N点DFT和N+1点DFT，再利用两次DFT计算结果进行线性插值得到信号真实频点上各次谐波的实部和虚部，计算出信号各次谐波的幅值和瞬时相位。仿真分析和实际测量表明，该算法的计算精度和实时性较高，能够满足频率随机变化的应用要求。%In order to seek a real⁃time phasor calculation method which is independent of frequency,a sinusoidal phasor in⁃terpolation calculation method based on variable data window is proposed in this paper on the basis of analysis of the traditional algorithm. With the algorithm,the sample data of signal in around one cycle is obtained by equal interval sampling,the funda⁃mental frequency is calculated according to the sampling data,and the maximum sampling points N needed in a single period is determined. And then the signal N point DFT and N+1 point DFT are calculated,and the real part and the imaginary part of each harmonic wave at real frequency point of signal is found out by means of the linear interpolation calculation according to the results of twice DFT calculations. At last the amplitude and instantaneous phase of each harmonic wave of signal are worked out. The simulation and actual measured results show that the accuracy and real⁃time performance of this algorithm are high, and can meet the application requirements of frequency random change.
展开▼
