| 摘要 |
PURPOSE: To provide a method for substantially reducing other order component errors and accurately detecting higher harmonic components by performing an averaging processing as a vector amount at the time of computing the higher harmonic components by a fixed sampling system. CONSTITUTION: Sampling data for one cycle of the fundamental frequency of measurement input are gathered, the gathered data are Fourier transformed, (n)-th order harmonic (n) is an optional integer} components are computed and the arithmetic result is decomposed into a real number component and an imaginary number component. After computing the similar calculation for the number of times of a point number equivalent to the one cycle of foundamental harmonics such as the case of advancing a sampling start phase for one sampling and the case of advancing it for two samplings, etc., averaging is performed as the vector amount and the valid value of the (n)-th order higher harmonics is obtained. Since the arithmetic result at the time of changing the sampling start phase for one cycle is obtained and the vector sum is taken, the influence of generating error components in the other order by the fundamental harmonics and higher harmonics provided in the measurement input is substantially eliminated. |
