V b Giam tdn that d i l n nang lUdi t r u y i n tai 220 &500kV(MWh) Tu hinh 3, biet tan suit giai cdng suit va cac mdc tdn that edng suit cua dy an, de d i n g danh gia dupc giam ton that dien nang hay hieu q u i Xin xem b i n g Bang 7- Danh gia h i l u qua g i i m tdn that d i l n nang t h i n g 5/ 2013 lUdi truyen tai 220 & 500 kV NPT xip xi tneu kWh KHOA HOC - CONG NGHE Q NGHIEN Cim ANH HirOlNG CHAT LirOiNG DIEN A P D £ N TON THAT DIEN NANG TREN LUOI DIEN \lK^mVi II (Sii|ifeili3iaeniian9lirtiliii)^laiNPT(liMil ^'kie 2.754^/6 •RwgS^n (£niton t ^ den nang (MW) Ldi tda soan: Bang cho thiy giam ton that dien nang thing 5/2013 tren ludi truyin tai 220 & 500 kV NPT nliieu hOn gan gap ba giam tdn that dien nang thang 5/2013 tren lUdi truyen tai 110 kV NPC (xem bang 5) Ndi each khiae, bat i^y du an nang cao hieu qua van hanli HTO nao thuc hien tren ludi 110 kV NPC deu mang lai hieu qua nhieu han cho ludi truyen tai 220 & 500 kV NPT Binh luan 4.1 DU an DA_TB 240 MVAr d l x u i t giai p h i p sir dung hop ly, hilu qua TBB h i l n ed HTD qude gia Theo quy dinh hien h i n h ciia EVN, TBB hiln cd tai cac tram bien ap 220/110 kVdo NPT quan ly, van h i n h Tuy nhien, vi hilu qua va lpi ich chung cua HTD, ed ludi truyen t i i 220 va 500 kV, cd the di chuyen mpt dung luong TBB h i l n ed tai eac tram bien ap 220/110 kV, bd tri lai tai mdt sd tram bien i p phu t i l l l O k V 4.2 Bit ky d U i n nang cao hieu q u i van hinh HTD nao thuc hien t r i n ludi 110 kV NPC deu mang lai hilu q u i nhilu hon cho lUdi truyen tai 220 & 500 kV NPT 4.3 Oanh gia hieu q u i kinh te-ky thuat ciia du an dupe dua t r i n hai ehi t i l u : (i) giam tdn that cdng suat truyen tren t i i lUdi 110,220 v i 500 kV (MW) va (li) t i l t kilm ton that dien nang (MWh) Giim tdn that edng suit truyin t i i ddng nghTa vdi giam chi phi edng suit l i p dat ngudn dien mdi (tdi thieu 33 ti VND/MW) Giim tdn that dien ning (MWh) ddng nghTa vdi giam chl phf p h i t dien, g i i m ehi phf truyen t i i dien (1 tneu VNO/MWh), g i i m p h i t t h i i hilu dng n h i kinh C02 (0.4 tan khf C02/ MWh) Vdi nhUng ehi t i l u ndi trin, d u i n DA_TB 240 MVAr cd gia tn kinh te-ky thuit ri't d i n g thuc hien Trong hai nam 2013 vd 2014, Hoi Dien lUc Viet Nam duac giao nhiem vu thuc hien 3e tdi "Nghien cdu dnh hudng chdt luong dien ndng den hieu qud id dung dien " khuon kho Chuang trinh muc tieu qudc gia vesCl dung ndng luang tiet kiem vd hieu qud De tdi GS VS TSKH Trdn Dinh Long, Pho Chu tich Hoi Idm chu nhiem De giup doc gia ndm dugc thong tin ve de tai Tap chise Idn lugtgidi thieu vemuc tieu, cdc noi dung nghien cUu, cung nhucdc ket qud cua de tdi Tgi so Tgp chi thdng 10 ndm 2013, Tda soan dd gidi thieu vdi dgc gid vi cdc muc tiiu chi'nh cua di tdi, phuang phdp nghiin cdu, cdc noi dung nghien cdu, tien tnnh thuc hien de tdi cung nhucdc sdn phdm nghiin cdu Tai so Tgp chi thdng I2ndm20l3, Toa sagn dd gidi thieu ve ton thdt dien ndng he thong diin (HTO), nguyen nhdn gdy ton thdt vd cdc gidi phdp di'gidm ton thdt dien nang Trong so Tgp chi ndy, Ida sagn xin duac di cap den chdt luong dien dp, cdc dang bien thiin diin dp, cdc dnh hudng cua chung vd cdc gidi phdp de ndng cao chdt luang dien dp Cac dang bien t h i l n dien ap C6 nhieu dang b i l n thien dien i p khac nhau, nhiln, chiing ta cd the phan eac loai b i l n t h i l n chii yeu sau day: - Biln thiln d i l n i p d i i han; - Bien thien d i l n ap ngan han, - Dao dong dien ap; -Qui diln ip T i i l i i u tham k h i o [TK] "LUdi dien mien Bic Viet Nam, bii edng suat p h i n khing", Trjnh PhUOng Thio & Pham Vilt Tiep, tap chi"Diln&Odi sdng" sd t h i n g 12/2012 Da dieu kiin khuon kho cua tdng so Tap chi cd hgn, trang so ndy chung toi xin tnnh bdy tdm tdt phdn bien thien diin dp ddi han, cdc phdn sau si duac trinh bdy Idn luat cdc so tiep theo Xin mdi quy dgc gid chu y theo ddi Oien A O&i songl 23 E] KHOA HOC - CONG NGHE t r i n eae phan tif v i dd lech dien i p tai cic nut tren HTO 1.1 Bien thien dien ap dai han: 7.1.2 Cdc nguyin nhdn Theo Uy ban Ky thuat dien Qudc te (International Electrotechmcal Commission) bien t h i l n dien i p d i i han (BOD) la sU thay ddi tri sd dien ap hieu dyng d tan sd HTD (50Hz hoac 60Hz}) k h o i n g thdi gian Idn hon phiit Cac nguyen nhan chfnh dan d i n BDD bao gdm: a Subien thien chdm cua phu tdi oJ Phon/oa/: BOD cdthe chia lam hai loai la thieu dien dp (undervaltage) va qud dien dp (overvaltage) Thieu dien dp la BOD dd tri sd dien ap hieu dung giam thap han ft nhat 10% so vdi dien dp danh dinh (nominal voltage) Qud dien dp ddi hgn la BOD dd tn sd dien ap hieu dung tang l l n it nhat 10% so vdi dien ap danh dinh 1.1.1 Cdc thdng so dde trUng Trong HTD, BOD thUdng dUpc diing de md ta sUthay ddi cua dien dp vdn hdnh (operating voltage) SU sai khac giUa d i l n ap van hanh va dien ap danh dinh bieu dien b i n g phan tram dien ap danh dinh goi la lech dien dp phan tram [1] ,.,, U - Udd • 100[%] Udd Trong (1) '^dd' Qdfl' ^dd' ^dd " ''"''^ ^° '^^"'^ '^'^^ '-'^^ ^°''^9 ^^^^' ^'^" ap v i tan sd; dp, dg, a, - Cac h i sd phu thudc loai phy tai Sy phu thudc v i o tan sd eiia phu tai cd the bd qua {a,^0) phan tfch trao lUu cdng suit v i tfnh toan dp iech dien ap Su phy thupc chi xet phin tieh cac qua trinh q u i Dien ap van hanh thay doi theo vj tri tren HTD tiiy thude sa dd ludi dien va trang thai mang tai cua he thdng Ton that dien dp (Voltage drop) tren mot mach dien la sy sai khac giCra tr; sd dien ap phfa cap dien va dien ap phia nhan dien cua doan mach: AU=IUil-IU2l Khi phan tich t r i o lUu cdng suit md hinh t i i cd the sU dung mpt eac dang dien hinh sau' (2) va fdVi thdt diin dp phdn trdm tUOng dng se la: Uii ^^^^Airar ^-^^-itra) I \°f U^^ - Oien ap danh dinh fV) till - Vi Su bien thien cua phu tai cd the dupc md phdng bdi dac tfnh phu t i i ed dang ham luy thifa nhu sau: Udd/ Trong do: U -Dien ap van hanh (V) AU%" Li sU thay ddi edng suit phy tai theo dd thj phu t i i (DTPT) Khi phu tai thay ddi van hanh, t r i o luu cdng suit tren HTD thay ddi dan den dd lech dien ap tai eac nut se thay ddi -Phy taic6ng suat kh6ng ddi: ap=aQ = - Phy t i i ddng dien khdng ddi: ap=aQ= - Phu tai tong trd khdng doi: ap - a^ = •100 (3) Trong qua trinh van hanh, theo sU thay doi cua phu tai ma ton that dien ap 5e thay doi dan den tri so dien ap va dp lech dien ap tai cac nut tren HTD cung thay doi Do do, luon CO quan he mat thiet giUa ton that dien ap Mdt phy t i i tdng q u i t l i td hop eua loai phu tii dien hlnh tren va cd the dUpc md phdng vdi cic he so Bp vaaQti/Odln Sy bil'n t h i l n ciia phu t i i cung ed the dupe md phdng bdi dac tinh phu tai co dang da thdc nhu sau tiiy theo loai phy tai [5]: Bdng Vidu mot so logi phu tdi mo phong dudi dgng da thdc theo dien dp Loai phu tSi P Q May dieu hoa 2,18 + 0,268U - 1,45U"' 6,31 - 15,6U + 10,3U^ Oen huynh quang 2,97 - 4U + U - ' 12,9 - 26,8U + 14,9U^ Dong CO khong dong bo 0,72 + 0,109U + 0,172U-' 2,08 - 1,63U + 4,08U' 241 Oien A Bai song KHOA HQC - CONG NGHE Q b Odng cdt cdc phan tO chinh HTD P + j(Q-Qc) Trong v i n hanh lu6n ed sUddng c i t eie phan tif HTD Vile ddng eit eie p h i n tCf nhu tu bu cdng suit Idn, cic phu tai Idn s l l i m thay ddi trang t h i i mang t i i cung nhU sa dd HTD va dan den su nhiy cap cua dp lich d i l n ap Ngoii cdn c6 the x u i t hien qua dp dien i p (C30DA) P+jQ ZL Vi du hlnh 1, Nut - Nut ngudn, g i i thiet cd dien ap khdng ddi Ddng tu bti CSPK tai nut phu t i i se l i m thay ddi tdn that d i l n i p t r i n nhinh 1-2 Vi U, khdng doi n l n suthay doi tdn that d i l n i p t r i n nhinh 1-2 cung chinh l i suthay doi (nhay cap, e j ciia dp lieh d i l n i p tai nut phu t i i 2, Hinh Bong tu bu CSPK Eu = 6UT, - 6Us = ^ ^ ^ • 100 = g ^ 100 Trong dd: dU^^ dU^ - Op lieh d i l n ap tai nut phy tai trudc v i sau ddng tu bii A U j r A U i - p _ A U g A U s -Tdn that dien ap t r i n doan mach -2 trude va sau ddng ty bii X,j-Dien khang doan maeh 1-2, Mat khic vdi ludi d i l n cao i p , ta cd y Trong dd ft; - ^ S ^ - Cdng suat ngin maeh tai niit phu t i i Do do, mdt each g i n dung, ta ed: Eu = ?^100 c Hiin tuang dao ddng cdng sudt cua mdy dien ddng bo Hiln tuong niy g i y nhCrng bien thien liln tue dd lech dien ap vdi biln dd ed the dat g i p hai l i n dien ap danh dinh eiia ludi diln Hay x i t trUdng hop mdt may p h i t d i l n ddng bd ket ndi vdi HTD nhu hinh Ja &- Er Hinh Dao dgng cdng sudt Oien A O&i songl 25 KHOA HOC - CONG NGHE Sure dien ddng eiia may phat va HTD lan lUOt la £ f = EfZCpjva £ H ~ ^H^VH Neu tdc dp quay cua may phat dong bd vdi tdc dp quay (tan so) cua HTD (Wf = < n ) khdng thay ddi, thi gdc lich = ( p f - Nguac lai viing ben trai diem tdi han se dng vdi viing HTD mat dn dmh, j „ ^ ^ Sup dd d i l n ipLli k i t q u i ciia mdt chudi cic sU kien kem theo mat dn dmh d i l n i p dan den giam thap d i l n ap tren mdt pham vi Idn eiia HTO 0.2 0.4 0.6 0.8 1.0 \2 1.4 a) Ddc tinh P-U cua HTO hinh 3.a 0.0 0.2 0.4 0.6 O.S I.O 1.2 b) Dgc tinh Q-U cua HTO hinh 3.a (Cdn nUa) Oien A O&i songl 27