Research On Generalized Harmonic Detection Method Of Hybrid Active Power Filter

With the increasingly serious of power quality issue such asharmonic, reactive power, negative sequence component and zerosequence component, there will be an important research value tointegrate them into generalized harmonic and comprehensivemanagement. As power electronic device which can governance powerquality, the hybrid active power filter has a excellent value for money.The governance effect of hybrid active power filter mainly based on thegeneralized harmonic detection result, therefore, this paper aims to studythe optimizated detection method of generalized harmonic, to improve theaccuracy and timeliness of detection.Firstly, the topology and classification of hybrid active power filterwas studied deeply, the working principle of four main function moduleswere introducted, so laid the theoretical foundation for the study of thedetection method of generalized harmonic.Secondly, according to the principle and detection requirements ofthe hybrid active power filter, analysed three aspects of the worklimitations of detection method based on traditional instantaneousreactive power theory, which included transformation matrix,phase-locked loop(PLL) and low-pass filter(LPF), paved the foundationway for the propose of the optimizated detection method of generalizedharmonic.And then, proposed a optimized detection method based ongeneralized instantaneous reactive power theory, which optimized in threeareas: Used apace transformation matrix instead of plane transformationmatrix, improved the reliability of the matrix transformation; in thephase-locked part of detection method, construction of single-phase andthree-phase generalized phase-locked loop, the sine and cosine signal offundamental positive sequence grid voltage was sync extracted by simplelogic operations and matrix transformation, improved the success rate ofthe phase-locked, and the accuracy of detection; in the low-pass part ofdetection method, proposed a generalized weighted morphological filter substituted the traditional low-pass filter, based on the theory ofmathematical morphology, used four kinds of basic operations ofmathematical morphology, by select the structural elements reasonably,the master-slave open-close and close-open iterative filter were proposed,combined with adaptive cancellation technology, made weighted operatedwith the sine and cosine signal of fundamental positive sequence gridvoltage respectively, exported DC signal based, to improve the real-timeof detection.Finally, the simulation comparative and experimental study werecarried on about the traditional detection methods and the optimizeddetection mentioned proposed by this paper, and results showed, undervarious conditions of single-phase or single-phase systems, both theresponse speed and detection accuracy of the optimized detection methodall better than the traditional detection method, so the effectiveness andfeasibility of optimized detection method was verified.