reactive power and voltage control-无功功率和电压控制

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1、专业外语测试翻译材料班级学号姓名成绩REACTIVEPOWERANDVOLTAGECONTROLForefficientandreliableoperationofpowersystems,thecontrolofvoltageandreactivepowershouldsatisfythefollowingobjectives:(a)Voltagesattheterminalsofallequipmentinthesystemarewithinacceptablelimits.Bothutilityequipmentandcustomerequipmentar

2、edesignedtooperateatacertainvoltagerating.Prolongedoperationoftheequipmentatvoltagesoutsidetheallowablerangecouldadverselyaffecttheirperformanceandpossiblycausethemdamage.(b)Systemstabilityisenhancedtomaximizeutilizationofthetransmissionsystem.AswewillseelaterinthissectionandinChapte

3、rs12to14,voltageandreactivepowercontrolhaveasignificantimpactonsystemstability.(c)ThereactivepowerflowisminimizedsoastoreduceRI2andXI2lossestoapracticalminimum(seeChapter6,Section6.3).Thisensuresthatthetransmissionsystemoperatesefficiently,i.e.,mainlyforactivepowertransfer.Theproblem

4、ofmaintainingvoltageswithintherequiredlimitsiscomplicatedbythefactthatthepowersystemsuppliespowertoavastnumberofloadsandisfedfrommanygeneratingunits.Asloadsvary,thereactivepowerrequirementsofthetransmissionsystemvary.Thisisabundantlyclearfromtheperformancecharacteristicsoftransmissio

5、nlinesdiscussedinChapter6.Sincereactivepowercannotbetransmittedoverlongdistances,voltagecontrolhastobeeffectedbyusingspecialdevicesdispersedthroughoutthesystemactivepowerbalance.Theproperselectionandcoordinationofequipmentforcontrollingreactivepowerandvoltageareamongthemajorchallenge

6、sofpowersystemengineering.Wewillfirstbrieflyreviewthecharacteristicsofpowersystemcomponentsfromtheviewpointofreactivepowerandthenwewilldiscussmethodsofvoltagecontrol.1ProductionandAbsorptionofReactivePowerSynchronousgeneratorscangenerateorabsorbreactivepowerdependingontheexcitation.W

7、henoverexcitedtheysupplyreactivepower,andwhenunderexcitedtheyabsorbreactivepower.Thecapabilitytocontinuouslysupplyorabsorbreactivepoweris,however,limitedbythefieldcurrent,andend-regionheatinglimits,asdiscussedinChapter5(Section5.6).Synchronousgeneratorsarenormallyequippedwithautomati

8、cvoltageregu