長距離供電線路波反射的研究.pdf

1、中國石油大學（華東）碩士學位論文長距離供電線路波反射的研究姓名：王峰申請學位級別：碩士專業(yè)：控制工程指導教師：馬文忠20081001ABSTRACTWangFeng(ControlEngineering)DirectedbyMaWenzhongWithminiaturization，multifunctionandhighperformanceofinverters，especiallytotaldigitalizationofcont

2、rolscheme，theflexibilityandadaptabilityofinvertersareimprovedcontinuouslyTherefore，invertersareusedinmodemindustrymorewidelyNowalmostallinvertersusePWMcontroltechnologiesHoweversomenotableadverseeffectsarefoundinthewidea

3、pplicationsofPWMinvertersFirstly，longcablebetweenPWMinvertersandmotorsleadstoovervoltageatmotorterminals，whichstressesonwindinginsulationsSecondly，voltagesourcePWMinvertersgeneratehigh丘equencycommonmodevoltage，whichinduc

4、eshighshaftvoltage，leadstobearingcurrent，andresultsinprematurebearingfailureTherefore，investigatingtheadverseeffectsofPWMinvertersanditscountermeasureshasimportantsignificanceInordertosuppresstheadverseeffectsandimprovet

5、hereliability，inverteroutputfiltersandcorrelativetechniquesofACvariablefrequencydrivesystemareinvestigatedinthisthesisInaccordingtotheaboveanalysisoftheory，passivefilteringtechniquestoeliminateovervoltageatmotorterminals

6、areinvestigated，includingmotorterminalfiltersandinverteroutputfiltersMotorterminalfiltersareinstalledatmotorterminals，whichcaneffectivelyreduceovervoltageandcannotbeusedwhenmotorterminalconnectionsarenotaccessibleInverte

7、routputfiltersarelocatedatinverteroutputterminalsThispaperusingtransmissionlinetheory，inverteroutputPWMvoltagesareconsideredastravelingwavesonthelongcablesDuetothedistributedparametersandhighdu／dt，voltagetravelingwavesar

8、ereflectedatmotorterminals，reflectedwavesaddincidentwaves，whichresultsinvoltagedoublingatmotorterminals，leadstoovervoltageandrings，andstressesonwindinginsulationsTheovervoltageisdependentonthePWMrisetimeofswitchingdevice