B Cng thng tp on in lc Vit Nam Vin nng lng Bo co tng kt ti cp b M s: I-150

7174 17/3/2009 H ni - 12/2008 Ch nhim ti: NguynMnh Cng NGHIN CUKH NNG NG DNG TRUYN TI IN MT CHIU TI VIT NAM ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 1 ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 2 ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 3Mc lc M u ............................................................................................................... 6CHNG I. TNG QUAN V H THNG TRUYN TI IN MT CHIU V XOAY CHIU .............................................................................. 71.1. Lch s pht trin cng ngh truyn ti in ..................................... 71.2. Cc thnh tu mi t c ca cng ngh truyn ti in. ........... 101.3. Cc yu cu k thut chnh ca tryn ti in siu cao p mt chiu . ......................................................................................................... 131.3.1. Thnh phn c bn .................................................................... 131.3.2. Trm chuyn i ....................................................................... 161.3.3. Cc kiu truyn ti in cao p 1 chiu .................................... 181.3.4. Nguyn l hot ng ca h thng truyn ti in 1 chiu ....... 211.3.5. u nhc im ca h thng truyn ti in cao p 1 chiu .... 241.3.6. Mt s h thng truyn ti in cao p 1 chiu trn th gii .... 25CHNG II. Cc yu t nh hng n chi ph u t h thng truyn ti in. ................................................................................................ 302.1. + nh hng ca cng sut v khong cch truyn ti. ................. 302.2. + nh hng ca cc yu t khc ................................................... 34CHNG III. Kho st s bin thin ca chi ph u t khi cc yu t u vo thay i. .............................................................................................. 393.1. Xc nh cc thnh phn ca chi ph u t .................................... 393.1.1. Phng php chung nh gi d n u t: ......................... 393.1.2. La chn phng php so snh kinh t d n u t cho n nghin cu kh nng ng dng truyn ti in 1 chiu Vit Nam ...... 413.2. Tnh ton chi ph trong trng hp yu t u vo thay i. .......... 42CHNG IV. ng dng trong cc trng hp c th ti Vit Nam. .......... 434.1. Cc gi thit a vo tnh ton: ....................................................... 434.1.1. Cc gi thit v mt k thut ..................................................... 434.1.2. Cc gi thit v mt kinh t ....................................................... 444.2. Tnh ton chi ph hin ti ha khi cc yu t u vo thay i ....... 464.2.1. M phng h thng in trong PSS/E ....................................... 464.2.2. Khong cch truyn ti 270 km ................................................ 494.2.3. Khong cch truyn ti 450 km ................................................ 584.3. Nhng d n truyn ti 1 chiu tim nng ...................................... 63 ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 44.3.1. Truyn ti in khu vc Nam Trung b - ng Nam B: ........ 634.3.2. Truyn ti in lin kt Vit Nam Trung Quc: .................... 64CHNG V. KT LUN ............................................................................ 66CHNG VI. PH LC ............................................................................. 676.1. M phng cc h thng in n gin: ........................................... 686.2. Vn u tv chi ph hin ti ha cho cc d n truyn ti in: . 82 ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 5Danh mc hnh v: Hnh : 1: K hiu cc Valve v cu chnh lu .......................................................... 14Hnh : 2: Cu hnh c bn mch chuyn i gm nhm van 6 xung ni vi MBA u Yo/Y ................................................................................................................... 14Hnh : 3: Cu hnh chnh lu 12 xung, s dng 2 MBA u Yo/Y v Yo/D ........... 15Hnh : 4: Thnh phn ca mt Thyristor Module ..................................................... 16Hnh : 5: Cu hnh c bn trm chuyn i AC - DC .............................................. 16Hnh : 6 : Cu hnh n cc, s dng b chnh lu 12 xung ................................... 18Hnh : 7: Cu hnh lng cc, s dng b chnh lu 12 xung. ................................ 19Hnh : 8 : Cc kiu u ni h thng truyn tiin 1 chiu .................................. 21Hnh : 9: hnh dng sng in p v dng introng qu trnh chuyn i ........... 21Hnh : 10: Bn v tr tuyn HVDC +/- 600kVItaipu - Sao Paulo ...................... 26Hnh : 11: Bn v tr tuyn HVDC 350kV Leyte - Luzon, Philipines ................. 27Hnh : 12: Bn v tr tuyn HVDC +/- 500kV Riland - Delhi, n ................ 28Hnh : 13: Bn v tr mt s d n HVDC trn th gii ...................................... 29Hnh : 14: Tn tht vng quang theo cao v tn tht truyn ti theo chiu di ... 32Hnh : 15: Chi ph u t khi P = 3500 MW ............................................................ 33Hnh : 16: Chi ph u t khi P = 10.000 MW ......................................................... 33Hnh : 17: Chiu di cch in cc cp in p khc nhau (Ngun ABB) ........... 35Hnh : 18: Mc tng tng i v yu cu cch in cao khc nhau .............. 36Hnh : 19: Ti trng dy dn cho EHVAC v HVDC .............................................. 36Hnh : 20: s mch yu cu khi truyn ti 6000 MWbng HVDC v HVAC ....... 37Hnh : 21: Thit k ct EHVACHnh : 22: Thit k ct HVDC ................ 38Hnh : 23: Bn v tr cc nh my in khu vc Nam trung b ........................... 50Hnh : 24: S khi h thng truyn ti ................................................................ 51Hnh : 25: th biu din tn tht theo cng sut truyn ti khi L = 270km ........ 53Hnh : 26: th biu din tn Vn u t theo cng sut truyn ti khi L = 270km .................................................................................................................................. 54Hnh : 27: th biu chi ph hin ti ha theo cng sut truyn ti khi L = 270km .................................................................................................................................. 55Hnh : 28: Sut u tcho TBA 765/500kV gim = 25.000 USD/MW ................. 56Hnh : 29: Sut u t cho TBA 765/500kV gim := 20.000 USD/MW ................. 56Hnh : 30: Sut u t cho ng dy 765kV gim = 1.0 triu USD/km ................ 57Hnh : 31: Sut u t cho ng dy 765kV gim = 1.0 triu USD/km ng thi sut u t cho TBA 765/500kV gim = 25.000 USD/MW .................................... 57Hnh : 32: Bn v tr tuyn truyn ti lin kt Vit Nam - Trung Quc .............. 59Hnh : 33: th biu din vn u t theo cng sut truyn ti khi L = 450km ... 61Hnh : 34: th biu din chi ph hin ti ha theo cng sut truyn ti khi L = 450km ....................................................................................................................... 62Hnh : 35: Sut u t cho trm chuyn i AC-DC, DC-AC gim = 75 USD/kW 63 ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 6M u H thng in Vit Nam 12 nm gn y (1995-2007) c s pht trin mnh vi tc tng trng trung bnh 14,8%/nm, in thng phm nm 2007 t 58 t kWh, gp hn nmln nm 1995, cng sut max tng hn 4 ln, nm 2007t hn 11000 MW.Theo xu hng trn, p ng nhu cu cng sut v in nng cho 20 nm ti, d kin cn xy dng khi lng rt ln ngun, li in trn c 3 min Bc Trung Nam, ngoi ra cn phi nhp khu in t nc ngoi nh Lo, Trung Quc. Cng ging nh nhiu nc ang pht trin khc, qu trnh pht trin kinh t ca Vit Nam s hnh thnh nhng khu vc ph ti tp trung, l trung tm kinh t vng nh khu vc H Ni v T.P. H Chnh Minh. V l thuyt, cn xy dng cc ngun in ngay gn nhng trung tm ph ti ny nhm trnh chi ph truyn ti cao v phn b ti u ngun in. Tuy nhin, vi nhng ro cn k thut, mi trng khng cho php xy dng nh my in m phi di chuyn ra cc vng cch xa hng trm km. T pht sinh vn v la chn hnh thc v cp in p truyn ti va m bo an ton, tin cy, va em li li ch kinh t tt nht. Xy dng h thng in lin kt a quc gia cng tr thnh xu hng chung trnthgiinhmkhaithctiungunnnglngcgithnhthpnhthy in. S dng h thng truyn ti siu cao p 1 chiu s gip cho vic trao i in nng gia cc h thng in khng ng b nhng chi ph thng cao hn nhiu so vi truyn ti bng h thng xoay chiu. ti nghin cu kh nng ng dng truyn ti in 1 chiu Vit Nam s bcunhgicchnhthctruyntiAC500kV,AC765kVvDC+/-500kV ngviccmccngsutkhcnhau2vngtimnng:truynti270kmt NamTrungBvkhuvcTP.HChMinhv450kmtHonghe(VnNam Trung Quc) v khu vc H Ni. Kt qu nghin cu s gp phn gip cho cng tc quy hoch h thng in c ci nhn tng quan hn i vi cc cp in p truyn ti trong bi cnh ca Vit Nam. ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 7CHNG I.TNG QUAN V H THNG TRUYN TI IN MT CHIU V XOAY CHIU 1.1. Lch s pht trin cng ngh truyn ti in ThomasAlvaEdison(1847-1931)phtminhrainmtchiu,hthng truyn ti in u tin l h thng dng in mt chiu. Tuy nhin, in p thp, khng th truyn ti cng sut in 1 chiu i khong cch xa. u th k 20, vi s pht trin ca cng ngh my bin p v ng c cm ng, truyn ti in xoay chiu dn tr nn ph bin v l la chn s 1 ca cc quc gia trn ton th gii.Nm1929,cckscacngtyASEA(AllmanaSvenskaElectriska Aktiebolaget)ThyinnghincuvphttrinhhthngValveh quangthyngniukhinmngliainccsdngtrongtruyntiin mt chiu vi cng sut v in p cao. Cc th nghim u tin c tin hnh ti ThyinvMnm1930kimtrahotngcaccValvehquangthy ngn trong qu trnh chuyn i chiu truyn ti v thay i tn s. Sau chin tranh th gii ln th 2, nhu cu in nng tng cao khuyn khch nghincutruyntiinmtchiu,nhtlkhiphitruynticngsutixa hoc bt buc phi s dng cp ngm. Nm 1950, ng dy truyn ti mt chiu thnghiminp200kV,chiudi116kmcavovnhnh,tiint MoscowiKasira(LinXc).ngdycaopmtchiuutinca vo vn hnh thng mi nm 1954 ti Thy in, truyn ti 20 MW in p 100 kV, chiu di 98km s dng cp ngm vt bin ni gia o Gotland v t lin. Cng ngh truyn ti in mt chiu lun gn lin vi cng ngh in t cng sut.Nhngnm1960,hthngValvethrntrthnhhinthckhingdng Thyristor vo truyn ti in mt chiu. Nm 1972, cc Valves th rn c ng dnglnutinCanadatitrmBacktoBackEelRivercngsut320MW inp80kV.inpvnhnhlnnhthinnaycangdytruyntimt chiu l 600 kV, truynticngsut6300MWtthyinItaipuiSoPaulo (Brazil), chiu di 796km. Ngy nay, truyn ti dng in mt chiu in p cao l phn khng th thiu trong h thng in ca nhiu quc gia trn th gii. Truyn ti in siu cao p mt chiulunccnnhckhiphitilngcngsutrtlnikhongcchxa, lin kt gia cc h thng in khngng b hoc xy dng cc ng cp in ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 8vtbin.Vilngcngsutln,khongcchxa,truynticaopmt chiu s chim u th v chi ph u t v tn tht truyn ti so vi dng in xoay chiu 3 pha truyn thng. Trn th gii c 79 cng trnh truyn ti in 1 chiu c xy dng (trong c 33 trm Back to Back, 46 ng dy truyn ti), c 6 cng trnh s vn hnh giai on t nay n nm 2010 (2 d n M, 1 Trung Quc, 1 Na Uy H Lan, 1 Australia v 1Estonia Phn Lan). Hinc14hngmcngdysiucaop1chiu500kVangvnhnh trnthgiitrong5TrungQuc,3n,4MvCanada.Chiudi trungbnhca1ngdyl1174km,cngsuttikhongt1500n3000 MW. Danh sch cc d n truyn ti 1 chiu hin nay c trong bng sau: STTTn cng trnh HVDC Nm vn hnh / nng cp / d b Kh nng ti (MW) in p mt chiu (kV) quy m cng trnh B-B/ line/cable (km) V tr cng trnh Aang xy dng1ESTLINK2006350150106Estonia-Finland 2BASSLINK2005500400360Australia 3NORNED2007600500580Norway-Netherlands 4THREE GORGES-SHANGHAI20073000500900China 5NEPTUNE2007600500102U.S.A. 6MISSION200715021B-BU.S.A. Bang vn hnh1VANCOUVER 1196831226074Canada 2VOLGOGRAD-DONBASS1962720400470Russia 3SAKUMA1965/19933002 X 125B-BJapan 4NEW ZEALAND HYBRID1965/921240+270/-350612New Zealand 5PACIFIC INTERTIE1970/84/89/0231005001361U.S.A. 6NELSON RIVER 11973/931854+463/-500890Canada 7GOTLAND HVDC LIGHT1999506070Sweden 8DIRECTLINK20003 X 608059Australia 9MURRAYLINK2002200 150176Australia 10CROSS SOUND200233015040U.S.A. 11TROLL20042 X 406070Norway 12EEL RIVER19723202 X 80B-BCanada 13VANCOUVER 2197737028074Canada 14DAVID A. HAMIL197710050B-BU.S.A. 15SHIN-SHINANO 11977300125B-BJapan 16SQUARE BUTTE1977500250749U.S.A. 17CAHORA-BASSA197819205331420 Mocambique-South Africa 18C.U.19791128411702U.S.A. 19ACARAY19815026B-BParaguay ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 9STTTn cng trnh HVDC Nm vn hnh / nng cp / d b Kh nng ti (MW) in p mt chiu (kV) quy m cng trnh B-B/ line/cable (km) V tr cng trnh 20INGA-SHABA19825605001700Zaire 21EDDY COUNTRY198320082B-BU.S.A. 22CHATEAUGUAY1984 2 X 5002 X 140B-BCanada 23BLACKWATER198520057B-BU.S.A. 24HIGHGATE198520056B-BU.S.A. 25MADAWASKA1985350140B-BCanada 26MILES CITY198520082B-BU.S.A. 27OKLAUNION198522082B-BU.S.A. 28BROKEN HILL198640 2 x 17 (8,3 3)B-BAustralia 29CROSS CHANNEL BP 1+21986200027071France-U.K. 30IPP (INTERMOUNTAIN)19861920500784U.S.A. 31ITAIPU 119863150600796Brazil 32ITAIPU219873150600796Brazil 33URUGUAIANAI19875418B-BBrazil-Uruguay 34VIRGINIA SMITH198720050B-BU.S.A. 35FENNO-SKAN1989572400234Finland-Sweden 36MeNEILL198915042B-BCanada 37SILERU-BARSOOR1989100200196India 38VINDHYACHAL19895002 X 69.7B-BIndia 39RIHAND-DELHI19921500500814India 40SHIN-SHINANO 21992300125B-BJapan 41BALTIC CABLE1994600450255Sweden-Germany 42KONTEK1995600400171Denmark-Germany 43WELSH1995600162B-BU.S.A. 44CHANDRAPUR-RAMAGUNDUM199710002 X 205B-BIndia 45CHANDRAPUR-PADGHE19981500500736India 46HAENAM-CHEJU1998300180101South Korea 47LEYTE-LUZON1998440350443Philippines 48VIZAG 11998500205B-BIndia 49MINAMI-FUKUMITZU1999300125B-BJapan 50KIl CHANNEL20001400250102Japan 51SWEPOL LINK2000600450230Sweden-Poland 52GRITA2001500400313Greece-Italy 53HIGASHI-SHIMIZU2001300125B-BJapan 54MOYLE INTERCONNECTOR2001 2 X 2502 X 25064Scotland-N.Ireland 55TIAN-GUANG20011800500960China 56THAILAND-MALAYSIA2001600300110Thailand-Malaysia 57 EAST-SOUTH INTERCONNECTOR200320005001400India 58RAPIDCITYTIE20032X10013B-BU.S.A. 59THREE GORGES CHANGZHOU20033000500890China 60GUI-GUANG20043000500936China 61 THREE GORGES-GUANGDONG20043000500900China 62LAMAR200521163B-BU.S.A. 63VIZAG 2200550088B-BIndia 64KONTI-SKAN 1 AND 21965/88/2005740285150Denmark-Sweden ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 10STTTn cng trnh HVDC Nm vn hnh / nng cp / d b Kh nng ti (MW) in p mt chiu (kV) quy m cng trnh B-B/ line/cable (km) V tr cng trnh 65SACOI1967/85/93300200385Italy-Corsica-Sardinia 66SKAGERRAK 1-31976/77/931050250/350240Norway-Denmark 67NELSON RIVER 21978/852000500940Canada 68HOKKAIDO-HONSHU1979/80/93600250167Japan 69VYBORG1981/82/84/02 4 X 355 1 X 170 (85)B-BRussia-Finland 70GOTLAND Il-Ill1983/8726015098Sweden 71QUEBEC-NEW ENGLAND1986/90/9222505001500Canada-U.S.A. 72GESHA1989/9012005001046China 73GARABI 1&22000/02200070B-BArgentina-Brazil 74RIVERA 70 B-BUruguay 75SASARAM2002500205B-BIndia C d b1KINGSNORTH1972/1987640 82England 2DUERNROHR 11983/1997550145B-BAustria-Czech 3ETZENRIHT1993/1997600160B-BGermany-Czech 4VIENNA SOUTH-EAST1993/1997600145B-BAustria-Hungary *Ngun:StandardHandbookforElectricalEngineers,Fink,DonalG.-McGraw-Hill Pro. Publishing, 2006, page1015. *Ch thch: B-B:trm Back to Back. 1.2. Cc thnh tu mi t c ca cng ngh truyn ti in. T nhng nm 1980s tr li y, s pht trin ca khoa hc cng ngh lm cho cng ngh truyn ti in c nhng bc tin vt bc. *) Cng ngh siu dn: Cngnghsiudnnhitcao(High-temperaturesuperconducting technology - HTS)ang c xu hng pht trin nhanh chng. Dy dn s dng vt liu siu dn chu nhit c th cho php dn dng ln gp 2-3 ln dy dn thng. Vtliusiudnhincsdngtrongcpin,inplnn138kV.Cp insiudn(HTS-cable)phttrinnthhth3(bicngtyAmerican Superconductor AMSC, U.S.).ng dy cp siu dn di nht hin nay l 600 m, in p 138 kV, ti 574 MVA gia trm Holbrook vi h thng in o Long Island Power Authoritys system (USA), d kin vn hnh nm 2008. Ccngdytrnkhngsdngdynhmlicompositecththayth dy nhm li thp thng thng nhng cng sut truyn ti gp 2 ln, rt ph hp ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 11cho vic ci to h thng truyn ti in trong cc thnh ph ln v nhng ni hn ch v hnh lang tuyn.*) Xu hng thu nh quy m h thng in khuvcBcM,tngcngsuththnglinktphangl600.000 MW, cng sut h thng lin kt pha Ty l 130.000 MW. Khi mt pha b s c r li s c nhiu kh nng lan truyn sang pha bn kia. Hin ang c xu hng chia h thng ln thnh cc h thng in nh hn, gip cho vic qun l vn hnh tt hn.Cchthngnhslinktvinhaubngccngdycaop1chiu (HVDC)hocquacctrmchuyniBack-to-Back.ivincM,chiph cho vic ny vo khong 8 n 10 t USD (theo nghin cu ca hi ng hp tc nng lng ng Bc), nu so vi s c r li nm 2003 gy thit hi c tnh 6 tUSDthdntrnrtngquantm,nhtlkhisphttrincacngngh in t cng sut ang lm gim gi thnh ca h thng truyn ti 1 chiu (HVDC) v h thng truyn ti xoay chiu linh hot (FACTS). Hin nay, cng ty ABB Thy S pht trin thnh cng h thng truyn ti in mt chiu quy m nh c khong vi chc MW (HVDC Light) vi chi ph c thchpnhnc.HthngHVDCLightsdngcngnghTransitor2cc cng cch ly (IGBT) c chi ph thp hn nhiu so vi vic s dng Thyristor truyn thng.CngnghIGBTcnsdngtrongcctrmchuynicvaitrnh ngun p (Voltage source converter), gip gim cc s c ca h thng xoay chiu nhdaonginp,snghi,bcngsutphnkhng,CngnghHVDC LightcngdngM(ngcpvtbindi40km330MWni ConnecticutviLongIsland),Australia(180km200MWniMurrayLinkvi min Nam), lin kt M v Mexico (trm Back-to-Back 36 MW). *) My bin i tn s (gi tt l my bin tn quay) - VFT HngGEEnergy(Atlanta,US),phttrinmybintnVFTvariable frequencytransformerckhnngthayitnsvgcpha inpmt cch lin tc. Cng vi ng dng ca HVDC, my bin tn quay c th s dng lin kt 2 h thng in khng ng b. Hin my bin tn quay ang c s dng linkt2hthnginkhngngb,1tiQubec(Canada)v1tiLaredo (Texas). ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 12Ngoi lin kt cc h thng khng ng b, hin my bin tn quay ang pht trin cng ngh ng dng truyn ti cng sut gia cc h thng in ng b, trong trng hp ny, VFT ng vai tr nh b iu chnh gc pha, c s dng ln u tin ti h thng lin kt gia Pennsylvania vi trung tm New York, cng sut 300 MW. Ba gi d n khc vi tng cng sut 900 MW ang c thc hin ni gia Linden (New Jersey) vi New York (vn hnh 2009). *) ng dng ETO-Thyristor trong FACTS and HVDC PhngthnghimSandiaNationalLab.(U.S.)phttrinthnhcngloi ETOThyristor(EmitterturnoffThyristor),ckhnngphnngnhanh(5kHz), chu c dng ln (4kA) v in p cao(6kV), nhng c gi thnh thp hn nhiu so vi Thyristor thng thng. y s l loi Thyristor l tng cho h thng iu khinFACTSvccbchuyniHVDC.ETO-Thyristorhinangcpht trin trongccbbtnh(STATCOM),ngvaitrnhnhngb hpthusc li in (Grid shock Absorber). *) iu khin dng s c Cngvisgiatngcaquymhthngin,dngngnmchcngtng ln, dn n yu cu cn phi thay th thit b ang vn hnh. iu ny i hi chi ph ln. C mt cch khc khng phi nng cp thay th thit b, l s dng cc B gii hn dng s c - Fault current limiter (FCL) l s phi hp hot ng giacundycmkhngthpvcpsiudnchunhit(High-Temperature Superconductor cable-HTS cable). Cc b gii hn dng s c ang c lp t th nghim ti M v Nht Bn. Cc cng ty sn xut vt liu in siu dn ca M cng ang pht trin loi cp in s dng b n nh tr khng cao (high-Resistance stabilizer cable). Loi cp ny c c im, khi trng thi bnh thng, dng in c chy trong lp vtliusiudnHTS,nhngkhixyrasc, lptrkhngcaoshotngv cch ly s c, khi ht s c, lp siu dn li hot ng bnh thng. Nhnchung,sphttrincacngnghintcngsutcnhhngrt lnticngnghtruyntiinvquanimtruynti.Truynti in1chiu ang dn c ch v nhng u im trong cch ly s c xoay chiu, lin kt cc h thng in khng ng b, kh nng ti cng sut ln, t hnh lang tuyn v chi ph u t ngy cng gim. ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 13*)Nhngnlcphttrintrongtruyntiinsiu caop1chiuvxoay chiu: Hinnay,cngnghtruyntiinxoaychiuti800kVclmch vi 25 nm kinh nghim, v v nguyn tc, khng cn ro cn k thut no. Cng ngh truyn ti mt chiu +/- 600 kV cng c lm ch (kinh nghimtrn20 nm), ring cp in p trn +/- 600 kV th cn c pht trin thm, ch yu l th nghim thit b trong trm chuyn i. Cn i vi ng dy ti in, cc thng s thitkchoc2loitruyntihontonxcnh.Theothngk,nulm quytlitthmththngtruyntisiucaop1chiu+/-600kVcthhon thnhthitktrong3nm,cn1hthngEHVACcththitkxongtrong1 nm. 1.3. Cc yu cu k thut chnh ca tryn ti in siu cao p mt chiu 1.3.1. Thnh phn c bn Thnhphnkhngththiucabchuynicngsutincaopmt chiu(HVDC)lValve.NuValveccutotmthocnhiudiodescng sut mc ni tip th gi l Valve khng iu khin c, nu c cu to t chui thyristor th gi l Valve iu khin c. K hiu valve theo IEC (International Electrotechnical Commission) nh hnh v sau: Valve khng iu khin c(cu to t Diode) Valve iu khin c(cu to t Thyristor) ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 14 Cu chnh lu khng iu khin c Cu chnh lu iu khin c Hnh : 1: K hiu cc Valve v cu chnh lu Cuchnhlutiuchungm6valvexpthnh2dycminhhanh hnh sau: Hnh : 2: Cu hnh c bn mch chuyn i gm nhm van 6 xung ni vi MBA u Yo/Y Hu ht cc h thng chuyn i cng sut cao p 1 chiu s dng Thyristor u dng cu hnh cu chnh lu 12 xung. ti nghin cu khoa hc Nghin cu kh nng ng dng truyn ti in mt chiu vit nam Phng pht trin h thng in Vin nng lng 15 Hnh : 3: Cu hnh chnh lu 12 xung, s dng 2 MBA u Yo/Y v Yo/D Trong cu hnh trn, in p xoay chiu ln lt cp cho nhm Valves 6 xung, tng hp li, ta c nhm valve chnh lu 12 xung lch pha nhau 300, lm trit tiu cc dng in th t 5 v th t 7 pha xoay chiu, th t 6 pha 1 chiu, lm gim chi ph cho b lc sng hi 2 pha xoay chiu v mt chiu so vi b chnh lu 6 xung. Nhn vo hnh 3, i vi cc trm chuyn i s dng cu hnh chnh lu 12 xung, ta c 3 nhm, mi nhm gm 4 Valves theo chiu thng ng. Mi nhm 4 Valves ny c mc ni tip, xp thnh 1 khi thng ng. in p lm vic ca miThyristorhinnayvokhongvikV(