一种基于非同步采样的FFT算法.docx

第24卷第12期 中国电机工程学报 Vr01．24 No．12 Dec12月 Pmceedings of me CSEE @2004 Chin．Soc．for Elec．Eng文章编号：0258—8013(2004)12—0013．05 中图分类号：1M46 文献标识码：A 学科分类号：470-4051一种基于非同步采样的FFT算法 胡海兵，祁才君，吕征宇 (浙江大学电气工程学院，浙江省杭州市310027)A NoVEL FFT ALGoRITHM FoR NoNSYNCHRoNoUS SAMPLEHU Hailbing，QI Cai-jun，LU Zheng—yu(C01lege ofElectdcal Engineedng，Zhejiallg UniVersity，HaIlgzhou 310027，Zhejiang ProVince，China)ABSTRACT．111e leakage e胞ct is introducedby Fast Fourier caused maillly by 1a玛e capacity of noIllinear electricalTrallsfonn(FFT) in nonsynchronous sampling， which may 印paratus．Fast Fourier Transfonn(Fl可)is widelycause great errors in measu—ng hamonic coⅡlponents．Many adopted in h锄oIlics aIlalysis for its computadonⅡteratures had been issued to cope wim the problem using emciency．For calculanng precisely aJld emciently meweighted windows and interp01ations． HoweVer mesesignal par锄eters(f}equency，锄pHtIlde a11d phase)，twotechniques have to pmlong tlle sample duration to aVoid the conditions mustbe satisfied[11：①saIIlpled sigllals舢stmutual h釉onic interference．Based on me intensiVe allalysisbe廿uIlcated bV illteger_times of t11e fund姗ental cVcle．of tlle leakage effect，a simple fbmula is deduced between me ②NmI慨rof s锄pled dataⅣmust be equal to meleaked spectnlm aIld actual specnlJm．Tlle met圭lod retrieVes meof 2．However mmeseactual spec仇lm f而m me spectmm calculated by FFT wim power pracdcal applicadonsareconmct eachrelatively shon s锄ple du．ration wimom considering me conditions hard白o meet and o自Ien otller．1eakage effect aIld mutual interference among h姗onics． The开叩technique su脆rs limit撕ons iIl印phcations．Simulation results show the algorimm has lli曲er accuracy山aIl ManV ef约rts have been made to cope witll t11eseFFr aIld almost reconstmcts me actllal sDecm加1． drawbacks ll叫J．Most of tllese metllods or algorimmsfml into t11ese two categories：④In me time domainKEY WoRDS：Power system；Power quality；FI丌；LeakageEf!f色ct；H撇onic sllift tlle saI】叩led point