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所属单位：自动化学院

发表刊物：IEEE TRANSACTIONS ON POWER ELECTRONICS

关键字：Fourier transform harmonic detection phase-locked-loop three phase

摘要：Selective harmonic extraction plays an important role in power quality assessment, harmonic compensation, and so on. Among the various methods, discrete Fourier transform (DFT)-based algorithms has found wide and popular applications due to advantages like simplicity and excellent selectively filtering properties. However, DFT suffers from disadvantages like slow dynamics and sensitivity to frequency variations. In order to alleviate these drawbacks, an improved and extended DFT-generalized DFT (GDFT) is proposed. It is revealed in this paper that the conventional DFT can be viewed as a comb filter connected in series with complex resonators, and DFT relies on the mechanism of pole-zero cancellation for harmonic extraction. More importantly, the key reason behind the DFT slow transient responses is the large delay introduced by the comb filter. Therefore, this paper proposed to reconfigure the comb filter according to specific harmonic patterns of the input signal for improving the dynamic responses and system flexibility. The proposed GDFT not only maintains the advantages of simplicity and selectively filtering properties but also features fast transients, around 0.3 fundamental cycle for typical applications, which is much shorter than the one-cycle settling time of the conventional DFT. A phase-locked-loop block is also incorporated into the harmonic-detection system to deal with possibly large frequency variations in practical applications. Extensive tests are provided to validate effectiveness of the proposed method.

ISSN号：0885-8993

是否译文：否

发表时间：2018-04-01

合写作者：Liu, Huawu,Chen, Hao,Zhang, Li,邢岩

通讯作者：胡海兵