简介：基于有限元方法对热水器后壳的成形过程进行了分析,再现了实际冲压中所产生的起皱缺陷,分析了缺陷所产生的原因;通过对热水器后壳翻边工艺的调整,对成形结果进行了优化,提高了热水器后壳的制造质量,同时也验证了有限元模拟方法的适用性。

简介：TheConstructionMachineryDivision(CMD)intheRe-searchInstituteofElectricPowerConstruction(EPCRI)isaR&Dorganizationspecializedonconstructionmachineryandtechnologyforthermalpowerstationandtransmission&distributionprojects.Itwasestablishedin1964.Therearenow45scientificre-

简介：纵向压电应变常数d33是表征压电陶瓷材料机电转换性能的重要参数之一.有别于常规的静态、动静态检测方式,设计了一种基于扫频方法的新型d33参数测试装置.通过检测不同频率信号激励时线路的电流变化,实现压电陶瓷d33参数的检测计算.该装置具有性能参数检测操作方便、检测过程效率高等特点.

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简介：<正>ThepaperoutlinestheYangtzeThreeGorgeswaterconservancycomplex.ItdescribesthepowertransmissionanddistributionequipmentintheThreeGorgesLeftBankHydropowerStation,especiallylargehigh-voltagedistributiondevices.ItelaboratesthemeasuresforsuppressingGISover-voltageandthetestsonVFTO,besidestechnicalmeasurestoensuresafetyandstabilityofpowersysteminthestation.Italsomakessomeanalysesandsummariesabouttheproblemsencounteredinoperationoftheequipment.

简介：传统的螺纹板成型工艺通过焊接将螺母固定在板料上,其缺点是联结强度和定位精度不高,成型效率低,外表不美观.采用板料一体成型的新方法,通过板料拉深、整型、冲孔、镦挤出凸台,这种方法虽弥补了传统工艺的不足,但成型困难.为了在工艺设计阶段及时发现缺陷,采用有限元数值模拟对板料一体成型过程进行预测与评估,提出工艺改进方案以消除缺陷,并且给出了成型力以选择合适的压力设备.

简介：本文的目的是对于利用模拟渐近法来确定多速3相绕组的可能性进行探索。它局限于p/2p极性质的非常简单的情况。这个方案已得出了非常著名的解决办法；于是，就可以着手研究更加困难的问题了。

简介：TheDevelopmentof3DCADtechnologypresentsaneweffectivetoolindesigningoutdoorswitchyardforpowerplant.Anewlayoutpatternof330kVswitchyard(SWYD)ofalignedtypewasstudiedwiththismethod.Someissuesaboutcomputerized3DmodesappliedinSWYDdesignarealsodiscussedinthispaper.

简介：Accordingtoperformanceanalysisofathree-phasegrid-connectedinvertermathematicalmodelofadirectly-drivenwindturbinewithapermanentmagnetsynchronousgenerator(D-PMSG)underunbalancednetworkvoltageconditions,adualcurrent-loopcontrolstrategy(DCC)orientedonpositivevoltageandnegativecurrentisproposedtoinhibittheDCvoltagefluctuation.Meanwhile,anotchfilterisintroducedintotheconventionalcontrolstrategyofaphase-lockedlooptocompletethelowvoltageridethrough(LVRT)abilityofthewindgenerator.A1.5-MWD-PMSGwithaback-to-backIGBTfrequencyconverterwassimulatedinthePSCAD/EMTDCenvironment,andsimulationresultsshowedthat:themaximumwindpowertrackingwasachievedinthissystemandtheproposedDCCstrategycouldsuccessfullyinhibittherisingagingofDCvoltageandenhancetheride-throughcapabilityofD-PMSGwindgenerationsystemunderunbalancednetworkvoltageconditions.

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