Novel Method of High-accuracy Detection for Interharmonics

A novel approach of interharmonics detection based on improved total least square estimation of signal parameters via rotational invariance techniques(TLS-ESPRIT) is presented in this paper.TLS-ESPRIT belongs to subspace estimation in modern signal process.But the same multi-poles cannot be gained based on TLS-ESPRIT under the influence of the noise.Restore of multiple poles is presented to take the same multi-poles accurately and polynomial fitting is presented to detect amplitude accurately.Interharmonics analyses of the simulation signal,amplitude modulation signal and EAF current are done.The simulation results show that the method has high antinoise capability,higher detection accuracy and the better adaptiveness to the amplitude inter harmonics signal of time change especially.