【摘要】：換相失敗是直流輸電系統(tǒng)逆變器最常見的故障之一,通常故障清除后直流系統(tǒng)可以恢復(fù)換相,周期性換相失敗很少發(fā)生,過去國內(nèi)從未出現(xiàn)過換相失敗閉鎖直流的情況。通過對(duì)林楓直流現(xiàn)場數(shù)據(jù)的深入分析,得出換相失敗持續(xù)時(shí)間達(dá)到保護(hù)定值,保護(hù)正確動(dòng)作;而勵(lì)磁涌流引起楓涇站換流母線電壓畸變、閥控VBE對(duì)已關(guān)斷閥執(zhí)行重觸發(fā)以及換相失敗恢復(fù)期間直流電流過沖等因素是導(dǎo)致林楓直流發(fā)生周期性換相失敗的主要原因。在此基礎(chǔ)上,基于電磁暫態(tài)程序建立了林楓直流輸電研究模型,其中控制保護(hù)采用了與實(shí)際工程一致的詳細(xì)模型,通過仿真研究提出了極控系統(tǒng)的改進(jìn)措施:取消瞬時(shí)電流控制、優(yōu)化換相失敗預(yù)測和低壓限流等功能,最后在林楓直流輸電工程中進(jìn)行了現(xiàn)場驗(yàn)證試驗(yàn),試驗(yàn)結(jié)果驗(yàn)證了所提措施的有效性。
【圖文】：

highvoltagemaintransformer500kVsideenergizingtest,bipolarperiodicalcommutationfailureinLinFengDCtransmissionsystemoccurred,after2.6sthreeprotectionsystemofLinFengbipolarreportedcommutationfailureandthenLinFengHVDCbipolarblocked.1.1OperatingStateBeforeFaultLinFengHVDCinvertersideislocatedatFengJingconverterstation,throughFengLian5107andFengTang5117double500kVACcircuitconnectstheLianTangstation,showedasFig.1,beforecommutationfailureoperatingstatusofAC/DCsystemisasfollows.圖1交直流系統(tǒng)接線Fig.1ThewiringdiagramofAC/DCsystemLinfengHVDC:bipolaroperatingwithfullvoltage,thepowerdirection:TuanLin-FengJing,bipolartransmissionpowerwas1740MW.Liantangsubstation:1000kVsidebreakersincoldstandbystate;500kVside,5042,5043,5092,5093breakersincoldstandbystate,therestofthe500kVsidebreakerswererunning;110kVsidebreakerincoldstandbystate.LianTangstationNo.2andNo.4maintransformerswereincoldstandbystate,1000kVAnTangIandIIlineswereinmaintenancestate.1.2TheCommutationFailureProcessAccordingtoLinFengtransientfaultrecorder(TFR)andeventlists,beforeDCblocking,11timescommutationfailureoccurredineachpoleandtheintervaltimeofthecommutationfailurewas220~260ms.ThedurationfromthefirstcommutationfailuretoDCblockingwas2.6s,thensatisfiedcommutationfailureprotectionblockingconditions,DCprotectionsystemactedcorrectlyaccordingtosetlogic.

第38卷第10期電網(wǎng)技術(shù)2673LianTangstationclosed5043breakerandenergizedNo.21000kVextra-highvoltagemaintransformer.Thenperiodicalcommutationfailureoccurred,asshowninFig.2.Comment:inthefigureUacisconverterbusthree-phasevoltage,IVYisYYconvertertransformervalvesidethree-phasecurrent,IVDisYDconvertertransformerthree-phasecurrent,thefollowingissameasthese.圖2林楓直流換相失敗閉鎖整體過程Fig.2ThewholeprocessofLinFengHVDCcommutationfailure1.3TheMechanismofPeriodicCommutationFailureCommutationfailureisoneofthemostcommonfaultsatHVDCsysteminverterside.DCsystemusuallycanrestoretothenormalconditionsafterfaultclearancesincethechanceislowforperiodiccommutationfailure.ThroughthedataanalysisofLinFengproject,itisconcludedthatthreefactors,includingmagnetizingsurgecurrentleadingtothebusvoltagedistortionatFengJingconverterstation,valvecontrolVBEretriggeringtheclosedvalveandDCovershootingduringcommutationfailurerecovery,arelikelytocauseLinFengHVDCperiodicalcommutationfailure.Amongthem,themagnetizingsurgecurrentcausingtheconverterbusvoltagedistortionismostcommoninformingcommutationfailure.Therefore,thisworkmainlyfocusonadetailedanalysisoftheothertwofactors.1)ValvecontrolVBERetriggerAnalysis.Fig.3showsthewaverecordofpole2圖3現(xiàn)場極2換相失敗錄波Fig.3TheprojectcommutationfailureTFRofpole2commutationfailure.FromFig.3,thecommutationfailureoccursatbothYandDbridgessimultaneously.Inmeanwhile,thesetwocommutation
【作者單位】： 北京交通大學(xué)電氣工程學(xué)院;中國電力科學(xué)研究院;中國普瑞科技有限公司;丹佛大學(xué)電子與計(jì)算機(jī)工程系;
【分類號(hào)】：TM721.1

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相關(guān)期刊論文 前4條

1 李新年;李濤;王晶芳;胡濤;;云廣±800kV特高壓直流對(duì)南方電網(wǎng)穩(wěn)定性的影響[J];電網(wǎng)技術(shù);2009年20期

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本文編號(hào)：2523265