To enhance the quality of manufacturing as responsibility, build national brand of measurement!
To enhance the quality of manufacturing as responsibility, build national brand of measurement!
FFT变换，输入数据应该是2^n个，因此，有N=2^n，
输出的N个数中，前N/2个和后N/2相同，只需要前N/2个，记为M
第一个数代表直流分量，也称零次谐波；
第二个数代表基波，也称一次谐波；
第三个数代表二次谐波；
...
第M个数代表M-1次谐波。
上述说的数都是复数，用an+jbn表示：
幅值magn=√2/2*√(a^2+b^2)；
相位φn=arctan bn/an
作者：hb_yinhe
湖南银河电气有限公司(http://www.vfe.cc)
China's leading enterprise in variable frequency power measurement and metering
National variable frequency power measuring instrument (metering station) founder
Research and development unit of national variable frequency power metering standard