An open loop frequency estimator for adversely distorted signals encompassing interharmonics

Abstract

This paper proposes an open-loop frequency estimator (FE), with high harmonic rejection potential and a good dynamic response. First, the Sliding Goertzel Transform (SGT) is utilized to extract the orthogonal components that provide the means for evaluating the phase angle. The output angle of the SGT is further processed using the differentiation filter to estimate the frequency under the adverse conditions. The efficacy of the proposed FE is established after rigorous testing under various prevalent MicroGrid-level harmonic, interharmonics polluted, dynamic test signals. The performance of the proposed FE is also compared with four other existing FEs, and the results are found to be very encouraging. Furthermore, the proposed FE is implemented on the dSPACE MicroLabBox, validating its excellent performance through various experimental results.