A fast GST with frequency correction for estimation and tracking of harmonic and inter-harmonic frequencies in power signals

Abstract

An alternate method based on Generalised S-transform (GST) is proposed for identification of harmonic, Inter-harmonic and sub-harmonic frequency in power signals. A selective frequency partitioning with reciprocal signal cropping is introduced to significantly reduce the computational demand of the GST algorithm. The proposed selective frequency partitioning is chosen such that the bins at dominant frequencies are taken into account. Further, a Jacobsen estimator with bias correction is used for the frequency correction. Thus, the proposed method reduces the error caused by the leakage affect in the GST and accurately estimates the harmonic and inter-harmonic frequencies.