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ID:29719091
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时间:2018-12-22
《含风电场的电力系统静态电压稳定性分析翻译》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、燕山大学本科毕业设计(论文)英文翻译课题名称:含风电场的电力系统静态电压稳定性研究学院(系):电气工程学院年级专业:09级电力四班学生姓名:张建春指导教师:王珺完成日期:2013.5.8一Theinterductionofsteady-StateCharacteristicsthespeed-torquecharacteristicisquitelineararoundsynchronousspeed.Iftherotorspeedisbelowsynchronousspeed,theinductionmachineisoperatingasa
2、motorandiftherotorspeedisabovesynchronousspeed,theinductionmachineisrunningasagenerator.themechanicalpowerandthemechanicaltorquearegivenbytheslip,rotorresistanceandtherotorcurrent.Thespeed-torquecharacteristicoftheinductionmachineisquitelineararoundsynchronousspeed.thetorque
3、isproportionaltotheinverseoftherotorresistance.Thisimpliesthatitispossibletohaveexternalrotorresistancesconnectedinserieswiththeexistingrotorresistancesofawound-rotorinductionmachine.Bychangingthevalueoftheexternalrotorresistanceitispossibletochangetheslopeofthespeed-torquec
4、haracteristic.Onedisadvantagewiththismethodisthatitisonlypossibletoincreasetheslipusingtheexternalrotorresistances.Thisimpliesthatiftheinductionmachineisrunningasamotor,thenanincreasedrotorresistancewilldecreasetherotorspeed.Ontheotherhand,iftheinductionmachineisrunningasage
5、nerator,theniftherotorresistanceincreases,therotorspeedwillalsoincrease.Beforesemiconductorswereavailable,onewayofadjustingtheslipwastointroduceexternalrotorresistances.Theexternalrotorresistancewillcauseadditionallossesintherotorcircuit.Whensemiconductorsbecameavailableitwa
6、spossibletorecovertheslipotherwisedissipatedintheexternalrotorresistance.Thus,theslippowercanberecoveredintomechanicalorelectricalenergy;therefore,thismethodiscalled"slippowerrecovery."Therotorcurrentmustberectifiedwithadioderectifier.Formotoroperation,therotorcircuitwillsee
7、thedioderectifierasaresistanceandthereforethismethodwillworkapproximatelyinthesamewayasfortheexternalrotorresistances.Notethatthedioderectifiercannotbeusedingeneratoroperation.Therectifiedcurrentcouldbeconvertedtomechanicalpowerusingadcmotorcoupledtotheshaftoftheinductionmot
8、ororfedbackintothegrid.SinceKramerdriverequireanextradcmotoritisofnointeres
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