Open AccessPrecise algorithm for frequency estimation under dynamic and step‐change conditions
Author(s) -
He Zhengyou,
Fu Ling,
Han Wenzhen,
Mai Ruikun,
Dong ZhaoYang
Publication year - 2015
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2014.0107
Subject(s) - phasor , algorithm , taylor series , computer science , fast fourier transform , estimation theory , control theory (sociology) , mathematics , power (physics) , electric power system , artificial intelligence , mathematical analysis , physics , control (management) , quantum mechanics
To achieve fast‐response frequency estimation under step‐change dynamics as well as accurate frequency estimation under slowly varying dynamics, a dynamic‐model‐based frequency estimation with step‐change detection (DFESD) algorithm is proposed in this study. In DFESD, the derivative of the initial phasor estimation, which is obtained from short‐time Fourier transform and the first‐order Taylor‐expansion phasor model, is used to detect the step changes in signals. Then, the initial estimations are adaptively selected by the data‐selection strategy to estimate the frequency, of which the estimation is based on a high‐order Taylor‐expansion model to express the dynamic characteristics in signal. DFESD is a Taylor‐expansion‐based algorithm and it avoids the states mixture of both pre‐ and post‐ step‐change data within one long data window, so it can track the frequency accurately under slowly varying dynamics and give fast‐response estimation under step‐change dynamics. Performance of the proposed algorithm is evaluated by computer‐simulated and electromagnetic transients including DC (EMTDC) generated signals, and the results prove the efficiency of DFESD for accurate or fast‐response frequency estimation under various test cases.