简介:ThispaperisdevotedtopredictAClossofcableinconduitconductor(CICC)whichisofimportanceinthedesignofconductors.Theconsiderationfortheconductor'sdesignandmainparametersforthemagnetsareintroduced.InordertoattainagoodaccuracyinthecalculationofAClosses,thefielddistributionwithinsuperconductingoutsertshouldbeconsidered.CalculationoftheAClosses,includinghysteresislossesandcouplinglosses,isconducted.Anemphasisisputonthehysteresislossduringtherampupofthecurrenttotheoperationalcurrent(15.3kA)andthecouplinglossoftheconductorinapower-downconditionforinsert.Theresultsareobtainedtobe74.9kJand950Jfor40Thybridmagnets,respectively.Basedonthecalculation,abriefanalysisoflosseseffectontheconductordesignandtheoperationofmagnetisgivenforthepurposethatthecapacityofthecryogenertorcanbeevaluatedandthestabilityregimecanbeimprovedinourfutureworkonthehybridmagnets.
简介:ThesemiconductingpropertiesofanodicfilmformedonPbin4.5mol.dm-3H2SO4solu-tion(30℃)at0.9V(vs.Hg/Hg2SO4)for2hwerestudiedusingACimpedancemethod.ThephasecompositionofthefilmisPbSO4andPbO.PbSO4.Thesemiconductingpropertiesareduetothelatter.TheMott-Schottkyplotsshowthatthesaidfilmisann-typesemiconductorwithflat-bandpotentialof-0.9V(vs.Hg/Hg2SO4)anddonordensityof1×1016cm-3.Thesurfacedensitymeasuredat410—2500Hzis(2—5)×1012cm-2eV-1.
简介:Thispaperpresentsanoveltransformermagneticbiasingcontrolmethodforhigh-powerhigh-performanceACpowersupplies.Seriousconsequencesduetomagneticbiasingandseveralmethodstoovercomemagneticbiasingarefirstdiscussed.Thecausesofthetransformermagneticbiasingarethenanalyzedindetail.Theproposedmethodisbasedonahigh-passfilterinsertedintheforwardpathandthefeedforwardcontrol.Withouttestingmagneticbiasingoftransformer,thismethodcaneliminatemagneticbiasingoftransformercompletelyinreal-timewaveformfeedbackcontrolsystemsthoughtheaeroerroroftheHalleffectsensorsvarieswithtimeandtemperature.Themethodhasalreadybeenemployedina90KVAACpowersupply.Itisshownthatitoffersimprovedperformanceoverexistingones.Inthismethod,nosensorsareusedsuchthatthezeroerroroftheHalleffectsensorshasnotanyinfluenceonthesystem.Itissimpletodesignandimplement.Furthermore,themethodissuitableforvariouspowerapplications.
简介:DopedSrTiO3capacitor-varistormultifunctionalceramicswerefabricatedbyasinglesinteringprocess.ACcompleximpedanceanalysiswasperformedtoinvestigateelectricalfeaturesofgrainsandgrainboundariesforbothas-reducedceramicandreoxidizedceramics.Theresultsshowedthattheas-reducedceramicexhibitedinductiveresponseathighfrequenciesabove2MHz,whichisattributedtothecontributionofelectronbehaviorinsemiconductinggrains.Thehighfrequencyinductiveresponsedisappearedinimpedanceplotsofreoxidizedceramics.
简介:<正>ChinaSouthernPowerGridisauniqueEHVAC/DChybridtransmissionnetworkthatoperatesinChina.Initsservicearea,thedistributionofenergyresourcesandthedevelopmentofeconomyareextremelyunbalanced,solong-distanceandbulkpowertransmissionareneeded;besides,thegeographyandclimateconditionsareserious,rains,fogs,lightningandtyphoonaswellashightemperaturearecommonalltheyearround.Facingthesechallenges,thepowergridenhancedstabilitycontrol,improvedtheequipmentandstrengthenthenetworkstructure.Inthefuture,thepowergridplanstooptimizethedispositionofpowersourcesandbuilddigitalizedpowersystem.
简介:摘要:随着经济社会发展,车辆增多,废弃轮胎会逐年增加,用废弃轮胎制造的橡胶粉是一种良好的沥青改性剂,可有效改善沥青砼路面的使用性能;目前我国尚无专门的沥青混凝土施工规范,本文提供一些施工要点及数据,以供参考。