資源描述:
《陡波前過(guò)電壓替代波形研究》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在工程資料-天天文庫(kù)。
1、華北電力大學(xué)(保定)碩士學(xué)位論文波前過(guò)電空代波翌的研究名:楊欣桐申請(qǐng)學(xué)位級(jí)別:碩士空業(yè):電氣工程;電壬理論與新技術(shù)指導(dǎo)教師:蘭生英2011-03摘要在GIS屮快速暫態(tài)過(guò)電壓對(duì)變壓器等高壓電氣設(shè)備的絕緣危害很大,所以電氣設(shè)備出廠Z前需要做電氣設(shè)備的絕緣實(shí)驗(yàn)和仿真,但現(xiàn)在還沒(méi)有比較準(zhǔn)確的VFTO替代波形,本文主要研究的VFTO替代波形,可以為高壓仿真提供較為準(zhǔn)確的特快速暫態(tài)過(guò)電壓輸入。本文應(yīng)用EMTP-ATP建立了500kV、750kV>1000kV電壓等級(jí)的GIS內(nèi)部模型。研究VFTO替代波形需要大量主變處的VFTO波形,通過(guò)改變線路、元件參數(shù)、操作方式得到了各個(gè)屯壓等級(jí)下變壓器
2、入口處的VFTO仿真波形。參考雷電波幅值的確定方法,應(yīng)用SPSS軟件計(jì)算了變壓器入口處的特快速暫態(tài)過(guò)屯壓幅值的期望和標(biāo)準(zhǔn)差。計(jì)算了變壓器入口處VFTO的99%累積概率密度所對(duì)應(yīng)的幅值。木文提出的VFTO替代波形表達(dá)式考慮了幅值、頻率、幅值加權(quán),并給出了它們的確定方法。最后得到了各個(gè)屯壓等級(jí)下的變壓器入口處的VFTO替代波形。分別用仿真波形和替代波形作為激勵(lì)對(duì)變壓器繞組進(jìn)行仿真計(jì)算,結(jié)果表明本文提出的波形可以較好的替代變壓器入口處的VFTOo依據(jù)仿真得到的電壓互感器入口處的VFTO,應(yīng)用變壓器入口處的VFTO替代波的計(jì)算方法,計(jì)算了電壓互感器入】」處的VFTO替代波。分別以替代波
3、和仿真波作為輸入,計(jì)算了電壓互感器二次端口的干擾電壓。對(duì)比結(jié)果表明,應(yīng)用替代波研究VFTO對(duì)二次設(shè)備的影響是可行的。關(guān)鍵詞:氣體絕緣變電站;特快速暫態(tài)過(guò)電壓;替代波形;二次端口AbstractInGIS,veryfasttransientovervoltageisdangeroustotheinsulationofhigh-voltageelectricalequipmentsliketransformer.Soinsulationexperimentandstimulationneedtobedonebeforetheelectricalequipmentapplied.Th
4、erearefewaccurateVFTOsubstitutionwaveformscurrently.Inthispaper,theVFTOsubstitutionwaveformsarestudied,whichprovidesmoreaccurateinputofVFTOforhigh-voltagestimulation.Inthispaper,theinternalmodelsofGISareestablishedrespectivelyfor500kV,750kV,lOOOkVvoltagelevel.Bychanginglines,componentparamet
5、ersandoperation,alargenumberofVFTOwaveformsarereceivedattheentranceoftransformerundervariousvoltagelevels.Referringtothemethodtogettheamplitudeoflightning,theamplitudesofVFTOarecountedbySPSSbycalculatingthecumulativeprobabilityanddensitycurvesofVFTO,theamplitudeiscorrespondingto99%oftheproba
6、bilitydensity.ThesubstitutionwaveformofVFTOpresentedconsiderstheamplitude,frequency,frequencyweighting.Themethodtogetthemisdiscussedinthispaper.ThentheVFTOsubstitutionwaveformsundervariousvoltagelevelsarcproduced?Thereisacomparisonbetweenthesimulatedwaveformsandsubstitutionwaveformswhoseeffe
7、cttotransformerwindings.Fromtheresults,itcanbeclearlyfoundthatthewaveformproposedinthispapercanreplacetheVFTOattheentranceoftransformer.AccordingtothegivenVFTOoftheentranceofvoltagetransformer,applythecalculationmethodofsubstitutionVFTOwaveattheent