简介：Inordertorealizethemodulardesignofthemicrogrid,thispaperproposedanewmodulartopologyfortheAC-DCmixedmicrogrid.Inthattopology,theACmicrogridunitandtheDCmicrogridunitwerepackagedtogetherbytheback-to-backconverter.Thebattery-supercapacitorhybridenergystoragesystemwasconnectedtotheDCbusofback-to-backconverter.Bythereasonabledesignonthebattery-supercapacitorhybridsystem,theenergystoragesystemcouldsupplytherapidpowerandenergysupportforthemicrogridspontaneously.Themathematicalmodelandthecontrolalgorithmofthatmicrogridtopologywerestudied.Bythesimulationanalysis,itcanbeconcludedthatAC-DCmixedmodularmicrogridtopologycouldoperatesteadilyonboththegrid-connectedmodeandtheisolatedmode.Furthermore,wecanconcludebythesimulationthatthedesignedmodularmicrogridcouldoperateuninterruptedwhenthemicrogridtopologyswitchedfromthegrid-connectedmodetotheisolatedmode.Theseamlessswitchingbecamethenaturalpropertyforthemodularmicrogrid.Asaresult,themodularmicrogridtopologycanbeconsideredasausualpower/loadmoduletorealizethefriendlypowerinteractionwiththepowergrid.

简介：Thispaperpresentsanoveltransformermagneticbiasingcontrolmethodforhigh-powerhigh-performanceACpowersupplies.Seriousconsequencesduetomagneticbiasingandseveralmethodstoovercomemagneticbiasingarefirstdiscussed.Thecausesofthetransformermagneticbiasingarethenanalyzedindetail.Theproposedmethodisbasedonahigh-passfilterinsertedintheforwardpathandthefeedforwardcontrol.Withouttestingmagneticbiasingoftransformer,thismethodcaneliminatemagneticbiasingoftransformercompletelyinreal-timewaveformfeedbackcontrolsystemsthoughtheaeroerroroftheHalleffectsensorsvarieswithtimeandtemperature.Themethodhasalreadybeenemployedina90KVAACpowersupply.Itisshownthatitoffersimprovedperformanceoverexistingones.Inthismethod,nosensorsareusedsuchthatthezeroerroroftheHalleffectsensorshasnotanyinfluenceonthesystem.Itissimpletodesignandimplement.Furthermore,themethodissuitableforvariouspowerapplications.

简介：Soft-switchingtechniquesareattractivetounity-power-factorAC/DCconverterintheviewofthesizereductionandEMIsuppression.Asoft-switchedboostPFCconverterhasbeenstudiedbasedonitstopologyanalysis,PSIMsimulationandcircuitexperiment.Aspeciallimitationofsoft-switchingtechniqueshasbeenfoundintheirAC/DCapplications.

简介：“落后就要挨打”，“落后就要服从”。短短20余年来，我们引进了迈克·波特、德鲁克、科特勒、彼得斯、柯林斯、舒尔茨等大师的管理理念，怀着朝圣的心情倾听着斯隆、韦尔奇、格鲁夫、亚柯卡、比尔·盖茨、郭仕纳的每一次嘬唇声。我们究竟师法何方？当年魏源寄望“师夷长技以制夷”，但是当兔子不打盹时，乌龟如何赶在兔子前边？柳传志的答案是，把兔子拖入泥沼。无疑，柳的智慧常常闪耀着中国传统人文价值的光芒，与柳同一辈的很多中国企业家，他们的管理精神其实也很中国。

简介：Thisletterstudiesandanalyzestheworkingfeaturesofmaincircuitoftri-levelboostPowerFactorCorrect(PFC)converterandtheadvantagesoftri-levelswitchconverterinaspectsofbearinghigh-voltageofpowercomponents,overallsystemlossandmagneticcomponentselectionbaseduponthesingle-levelboostPFCswitchconverter.Besides,relyingontheapplicationofmi-croprocessorinpowerconvertertechnologyandDSP(DigitalSignalProcessing)chip'sstrongcal-culatingcapacity,theletterpresentstheadoptionofmodifiedschemeoftri-levelboostPFCconverterunderthecontrolofpredictivecontrolalgorithm.Moreover,theoperatingprincipleandcontrolmethodarespecified,theresultsofcircuittestandanalysisareprovidedandtheadvantagesofpre-dictivecontroltechnology-basedmulti-levelboostPFCconverterisverified.

简介：安捷伦科技有限公司日前宣布安捷伦89600B矢量信号分析软件已提供802．11ac信号测试功能。这是市场中第‘个专用的802．11ac信号分析解决方案。

简介：继8月20日佳能公司在藏酷发布了EOS300D等新品之后。9月16日，佳能又携带一系列被赋予“影像文化引领者”使命的数码产品在北京中华世纪坛精彩亮相，这是佳能公司今年以来向影像市场发起的又一轮大型冲击波。此次发布的产品包括喷墨打印机、激光打印机、扫描仪、多功能数码照片打印机以及民用数码相机共计13款产品，涵盖了从输入到输出设备的所有领域。作为佳能数码产品始终如一的主题，“影像文化，尽在佳能”在此次发布会上拥有了更深层次的诠释：时尚办公．时尚生活。

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