基于乘法窗函数的插值FFT的谐波分析方法

An algorithm for harmonic analysis based on multiplication window function

针对常规加窗插值算法在使用过程中会出现不满足要求的情况,提出了一种新的乘法窗函数构造方法。以三种常规窗函数为例构造出九种乘法窗函数,并验证了基于这些乘法窗函数的三谱线插值FFT的谐波高精度分析方法。分析了新的窗函数的性能,将新窗函数应用到三插值FFT的谐波分析算法当中。仿真实验表明,构造出的窗函数在10个周期左右数据和5阶拟合条件下,相比于常规窗函数插值算法有更高的准确度。在实际工程中可根据需要选择所构造的窗函数。

The conventional interpolation windowed FFT algorithms will have a greater error when the number of the truncation is not enough. For this reason, a new construction method of multiplication window functions is presented to analyze electrical harmonics. Based on three conventional window functions, this paper constructs nine kinds of window functions and verifies an algorithm for harmonic high-precision analysis based on three-spectrum-line interpolation FFT. The performance of new window functions is listed, and the new window function is used for the harmonic analysis algorithm of three interpolation FFT. Simulation experiments show that the algorithms using multiplication windows has higher accuracy than using conventional window functions when the sample number length is about 10 periods and the polynomial is 5 order. In the practical engineering, the constructed window functions can be chosen as required.