Multi-Interharmonic Spectrum Separation and Measurement Under Asynchronous Sampling Condition

Steady signals of a power system sampled asynchronously will generate frequency spectrum leakage and fence effect. Meanwhile, in the case of the existence of interharmonics that are close to harmonics as well as other interharmonics, the actual frequency components cannot be accurately identified and measured on account of the limited frequency resolution. In order to solve the immeasurability of multiple adjacent interharmonics under asynchronous sampling condition due to spectrum interference, a multiple interharmonics spectrum separation and parameter measurement method is proposed. First, an interharmonic simplification model is established, and then, each main frequency component can be separated with the known spectral information using the spectrum separation algorithm. The performance of the proposed method is validated on the synthetic signal. The simulation results show that the proposed method can not only accurately identify the frequency components, but also obtain the parameters with high precision.