Calculation of Flicker Parameters Using Voltage Interharmonics

This paper proposed a new method to estimate voltage flicker using the discrete Fourier transform, which hope to obtain the parameters of voltage flicker while estimating interharmoncis. The proposed method obtains the amplitude, frequency and phase angle of each frequency component using the odd points interpolation correction method, which reducing the leakage while interpolating, based on the specified signal processing recommendations by IEC61000-4-7. According to the concept of voltage flicker, the double-band property of interharmonic-pair converted by voltage flicker was obtained. Considering voltage flicker perceptible frequency range, the interharmonic-pair frequency range can be obtained. According to the electric power distortion component symbiosis mechanism, we can differentiate interharmonic-pair and common interharmonics components, and obtain the parameters of flicker signal by amplitude modulation with sinusoidal carrier. Compared with the Square method and Prony method, the simulation results indicated the accuracy and validity of the proposed method; and the odd points interpolation correction method can separate harmonics from interharmonics effectively, and strongly restrain the spectral interruption.