41 12 2017 6 25 DOI10.7500/AEPS20170125007 Vol.41No.12June252017 1 1 2 1 3 (1. 310027;2. 650011; 3. 430074) ; ; ; ; 0 [4-5] [1] [6-7] [8-11] [2] [2] [12-13] [3] ( ) 2017-01-25; 2017-05-08 2017-05-15 (2016YFB0900104); MATLAB/ (51577168 ); Simulink 2 (yndw(2016)000303dd00124) 56
1 1(c) 1(b) 1(a) [14] PI 1(c) [15] 3 2 (1) (2) ( ) [2] d (3) 烄 1(b) P EU = UV sin(δ -α)=p umsin(δ -α) X Σ 烅 (1) P ES =I maxusin(δ +β+90 )= 烆 P smsin(δ +β+90 ) I ref d = Iref* d I ref* d I { max (2) I ref q ;P 1 E Fig.1 Controlblockdiagramandequivalent ;ωbase=100π circuitofdroop-controledinverter (4) 1(b) 2 I ref* I max 烄 q I mag I max 槡 I 2 max - (I ref* =烅 2 d ) I ref* d >I max I mag >I max I ref* d I max (3) 烆 0 I ref* d >I max P EU ; P ES ;V ;U ;X Σ ;I max ;δ ;α d V ; β I ;I ref d d I ref q d q ;I ref* d I ref* q d q ;I mag = (I ref* d 槡 ) 2 +(I ref* q ) 2 δ =Δωωbase (4) { Δω =ω -ω0 =m P (P 0 -P E ) ω ( );ω0 ( );m P ;P 0 htp//www.aeps-info.com 57
201741(12) O M S =P EO -P E (5) P EO O M S O (4) M M S=P um -P E (P um M ) (1) (4) A C 2 B D 2(a) 2.1 1(b) 1(c) α= 0 β =0 dq q q α β 0 2(b) α β 0 (1) (2) 2(c) O P EO (5) M S α β 2 Fig.2 Virtualpoweranglecharacteristiccurves 2.2 anditstransientdeviationphenomenon α β 2(a) M ; M O 2(a) 1(a) O I ref* d =O d +FI do (6) [2] { I ref* q =O q +FI qo 58
F ;I do I qo 3 F =0 X g d q ;O d O q T V qaxis(s) 2.5 Hz; F =0.6 PI T V qaxis(s) 10 Hz 3 I d I q I do I qo 3 烄 s I doest=i d -C est 1+T Vs Vd +ω0cestv q ( ) 烅 (7) s I qoest=i q -C est 1+T V LCL q -ω0c estv d 烆 Vs s ;C est LCL ;I doest I qoest d q ;T V ( T V =0.005s);V d V q LCL 4 d q P 0 A A A1 I do I qo I doest I qoest P 0 ( 4 A A P 0 (4) ) t=4s 0.2 0.8 t=7s 0.8 0.2 P sm =UI max P (7) 0 2(b) V q α V q V ref q T V qaxis(s) V q =T V qaxis(s)v ref q (8) [16-17] V q V ref q T V qaxis(s) 4 Fig.4 Transientinstabilitycausedbyvoltagesag 3 3 TV qaxis(s) Fig.3 BodediagramofTV qaxis(s) (9) 5(a) 烄 ω -ω0 = m ( P P 0 -P E ) I mag <I { max m P (P 0 -P E +S assist ) I mag I max 烅 S assist= ( K SP + KSI s ) ( Q E -Q assist ) 烆 (9) htp//www.aeps-info.com 59
201741(12) S assist ;K SP UI max<p 0 Q assist (14) K SI ; Q assist Q E Q assist (14) U> Q assist /I max-x ΣI max (9) Q assist X ΣI 2 max S assist sδ =ω-ω0 Q assist (14) (9) sδ =m Pω0[P 0 -P E + ( ) ( Q E -Q assist ) ] (10) K SP + KSI s (10) s (10) s s 2 δ =m Pω0[sP 0 -sp E + (sk SP +K SI )(Q E -Q assist )] (11) sp 0=0sP E=0s 2 δ =0 sk SP (Q E-Q assist )=0 (11) K SI (Q E -Q assist )=0 (12) Q E Q assist Q E δ Q E =Q assist P E P E = P 0+S assist d Q E =V q I d =(U q +X ΣI d )I d = 5 QE -δ (X ΣI max -Usinδ )I max (13) Fig.5 Transientcontrolstrategyforsynchronismand QE -δ curveduringcurrentsaturation Q E δ 5(b) (9) Q E -δ Q assist 5(b) Q E -δ E 1 E 2 E 1 E 2 ( ) E 1 E 1 Q E -δ Q assist 5(b) ( ) Q assist X ΣI 2 max -UI max Q assist X ΣI 2 max +UI max (14) E 1 2 δe1 (2) 5(b) E 1 P E =P 0 60
; α β A A2(c) PI 4 O d O q 1(a) O d O q ( PI d ±1.1) I max=1.05 S base= ; 10kVAV base= 380 Vωbase =1000rad/sL F = O d O q 0.05( )C F = 0.05( )L g+l l=0.2 ( )m P =0.02m Q =0.1P 0=0.8F=0.6 A A2(d) A2(e) K SP=10K SI=20Q assist=0.2 dq I ref* d I ref* q 4 30 0.4 I ref d I ref q 20 4.1 d ( (3)) t=2s ( ) P 0=0.3 P 0 =1.0 6 (7) C est ( α=0 ) 20% 2.1 A A2 4.2 U t=2s 1.0 0.7 t=8s 1.0 7 A ; 6 Fig.6 Trajectoryofinvertervirtualpowerangle duringapowerreferencestep A A2(a) V q V q 7 Fig.7 Trajectoryofinvertervirtualpowerangle 0 V q duringvoltagedropandrecovery V q A A3(a) A3(d) A A2(b) α β LCL d ( sin ) q (V d V q ) htp//www.aeps-info.com 61
201741(12) A A3(e) 50ms 2611. [4] [J]. 201236(6)39-44. I max=1.05 1.05 [5] 0.2 5 2 1 ;2 201360(6)2237-2250. 201530(7)3563-3576. (htp//www.aeps-info. com/aeps/ch/index.aspx) LUZongxiangWANGCaixiaMIN Yongetal.Overviewon microgridresearch[j].automationofelectricpowersystems 10.7500/AEPS20150709007. HUANG Linbin ZHANG Leiqi XIN Huanhai et al. Mechanism analysisofvirtualpoweranglestabilityindroop- controledinverters[j].automationofelectricpowersystems 201640(12)117-123.DOI10.7500/AEPS20150709007. [3]SIMPSON-PORCO J W D RFLER F BULLO F. Synchronizationandpowersharingfordroop-controledinverters inislanded microgrids[j].automatica201349(9)2603-. WU Yunya KAN Jiarong XIE Shaojun.Controlstrategy designforinvertersinlowvoltagemicrogrids[j].automationof ElectricPowerSystems201236(6)39-44.. [J]. 201539(2)39-45.DOI10.7500/ AEPS20140401008. XIAOZhaoxiaZHAO QianyuFANG Hongwei.Analysisand establishmentofstate-space equationsforinverter-interfaced microgrid[j].automationofelectricpowersystems2015 39(2)39-45.DOI10.7500/AEPS20140401008. [6]VILATHGAMUWA D MLOH P CLI Y.Protection of microgridsduring utility voltage sags[j].ieee Trans on IndustrialElectronics200653(5)1427-1436. [7]PAQUETTE ADIVAN D.Virtualimpedancecurrentlimiting forinvertersin microgrids with synchronousgenerators[j]. IEEETransonIndustryApplications201551(2)1630-1638. [8]POGAKU NPRODANOVIC MGREEN T C.Modeling analysisandtesting ofautonomousoperation ofaninverter- basedmicrogrid[j].ieee TransonPowerElectronics2007 22(2)613-625. [9]WANG X HRUAN XBLIUS Wetal.Fulfeedforwardof grid voltagefor grid-connectedinverter with LCL filterto suppresscurrentdistortionduetogridvoltageharmonics[j]. IEEETransonPowerElectronics201025(12)3119-3127. [10]LIW WRUAN X BPAN D Detal.Ful-feedforward schemes ofgrid voltagesforathree-phase LCL-type grid- connectedinverter[j].ieee TransonIndustrialElectronics [11]TAO YLIU Q WDENG Yetal.Analysisandmitigation ofinverteroutputimpedanceimpactsfordistributedenergy resourceinterface[j].ieee Trans on Power Electronics [12]ASTROM KJ.Limitationsoncontrolsystemperformance[J]. EuropeanJournalofControl200062-20. [13]ASTROM K J MURRY R M.Feedback systems an introductionforscientistsand engineers[m].new Jersey USAPrincetonUniversityPress2010. [14]ROCABERTJLUNA ABLAABJERG Fetal.Controlof powerconvertersinac microgrids[j].ieeetransonpower Electronics201227 (11)4734-4749. [15]ZHAO MYUAN X HU Jetal.Voltage dynamics of [1]. [J]. currentcontroltimescaleina VSC-connected weakgrid[j]. 200731(19)25-34. IEEETransonPowerSystems201631(4)2925-2937. [16]WANGJNICOL S C P CFENG X etal.designofa generalizedcontrolalgorithmforparalelinvertersforsmooth 200731(19)25-34. microgridtransitionoperation[j].ieee TransonIndustrial [2]. Electronics201562(8)4900-4914. [J]. 201640(12)117-123.DOI [17]LIU Q TAO YLIU Xet al.voltage unbalance and 62 harmonicscompensationforislanded microgridinverters[j]. IETPowerElectronics20147(5)1055-1063. ( 99 continuedonpage99)
PilotProtectionofPositiveSequenceImpedanceforDistributionNetwork withinverter-baseddistributedgenerator XU Meng 1 ZOU Guibin 1 GAO Lei 2 MA Yuwei 1 (1.KeyLaboratoryofPowerSystemInteligentDispatchandControl(ShandongUniversity)Jinan250061China; 2.JinanPowerSupplyCompanyofStateGridShandongElectricPowerCompanyJinan250001China) AbstractThefaultcharacteristicsoftheinverter-baseddistributedgenerator(IBDG)diferfromthoseoftraditionalresources whichmakesitdificultfortraditionalcurrentrelaytoclearfaultfastandreliably.alsoafectedistheactionperformanceof theexistingtransmissionlineprotectionprincipledirectlyusedindistributionnetwork withibdg.bydrawingoncurrent diferentialprotectionforreferencetheamplitudesofthedefinedpositivesequencediferentialimpedancefortheinternaland externalfaultareanalyzedandanovelpositivesequencediferentialimpedanceprotectionprincipleisproposedtoaccountfor theimpedanceamplitudediference.tofurtherimprovetheperformanceanoperationcriterionwithbrakingcharacteristicis constructedtoovercometheadverseefectsofloadbranch.anauxiliarycriterionbasedontheamplitudeofpositivesequence impedanceandcurrentisformulatedforinternalthree-phaseshortcircuitfaultswithouttransitionresistance.comparedwith thetraditionalcurrentdiferentialprotectiontheproposedprotectionstrategyhasnoneedforsynchronizedmeasurement.the feasibilityofprotectionschemeisverifiedbysimulationresults. This workissupportedby National High Technology Researchand DevelopmentProgram ofchina (863 Program) (No.2012AA050213)andShandongProvinceKeyPlanofResearchandDevelopment (No.2015GGX101011). Keywordspositivesequenceimpedance;diferentialprotection;brakingcharacteristic;inverter-baseddistributedgenerator (IBDG);distributionnetwork 櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧櫧 ( 62 continuedfrompage62) E-mailhaxwel@sina.com (1989 ) (1981 ) E-mailzhangleiqi@zju.edu.cn E-mailxinhh@zju. (1992 ) edu.cn E-mailhuanglb@zju.edu.cn (1980 ) ( ) ControlMethodsforImprovingVirtualPowerAngleTransientStabilityofDroop-controledInverters ZHANG Leiqi 1 HUANG Linbin 1 HUANG Wei 2 XIN Huanhai 1 HU Jiabing 3 (1.ColegeofElectricalEngineeringZhejiangUniversityHangzhou310027China; 2.DispatchingandControlCenterofYunnanPowerGridCorporationKunming650011China; 3.SchoolofElectricalandElectronicEngineeringHuazhongUniversityofScienceandTechnologyWuhan430074China) AbstractLikesynchronousgeneratorstransientinstabilityalsooccurstodroop-controledinverterswhensubjectedtolarge disturbances.owingtothecurrentlimitationthevoltageloopoftheinverterisoutofworkduringthedisturbanceandthe inverterturnstooperatinginthecurrentsourcemode.themechanismofthevirtualpoweranglecurvesdeviatingduringthe transientprocessbecauseofthelimitedvoltagetrackingperformancewhichreducesthestabilitymarginisfurtheranalyzed. Tothisendacurrentfeed-forwardcontrolmethodbasedonestimatingtheoutputcurrentisproposedtoimprovethevoltage trackingperformancesothatthetransientstabilityisimproved.besidestodealwiththelossofequilibriumpointsduringthe transientprocessatransientsynchronouscontrolmethodisproposed.ithelpstheinvertertoreachaproperequilibriumpoint whenthevoltageloopisoutofcommissionandpreventstheinverterfromtransientinstability.finalysimulationsonasingle- machine-infinite-bussystemverifytheefectivenessoftheproposedcontrolmethods. ThisworkissupportedbyNationalKeyResearchandDevelopmentProgramofChina (No.2016YFB0900104 )National Natural Science Foundation of China (No. 51577168 ) and Yunnan Electric Power Company (No.yndw (2016)000303DD00124). Keywordsinverter;virtualpowerangle;transientstability;currentlimiting;currentfeed-forwardcontrol;droopcontrol htp//www.aeps-info.com 99