| 摘要 |
A method of determining the fundamental component and the harmonics (I'(omega)) of a measured electric quantity (M) is described, where the measured quantity (M) is processed by an analog signal processing circuit (15), the processed measured quantity is sampled and subject to an analog-digital conversion with a subsequent discrete Fourier transform (DFT). To be able to determine very accurately the fundamental component and the harmonics (I'(omega)) of the measured electric quantity (M) despite the use of a relatively low quality signal processing circuit (15), a correction factor (k(omega)) characterizing the absolute value and phase of the frequency response characteristic of the signal processing circuit (15) is obtained from a memory (18). The measured values (I(omega)) of the absolute value and phase of the fundamental component and the harmonics after the Fourier transform are corrected with the correction factor (k(omega)).
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