Tap chi Khoa hpc va C6ng nghf 102 (2014) 012-016 Xac dinh so lan set danh tryc tiep tua bin gio dieu ki|n Viet Nam Determination of Number of Lightning Flash to Wind Turbine in Vietnam Nguyen Quang Thuan'', Tran Van Top'', Phqm Hdng Thinh' ' Truang Dai hoc Bach khoa Ha Noi - SS J, Dai cS Viet, Hai Bd Tnmg Ha Noi ^Truong Dat hoc Cong nghiep Ha Noi • Phumg Minh Khai, Qugn Bdc TicLiem, Thanh Pho Ha Noi Din Tda soan 19-02-2013 chdp nhan dang 25-08-2014 Tom tat Bai vi4t d4 xuat mot phuang phap xac dinh s6 ISn set d^nh tr{K tiep vao tua bin gid xem x^t dSn si/ thay ddi cao thu hut set theo vi tri quay cua cac canh du-a tr§n mo hinh di^n hinh hoc (EGM) Phuang phAp duac Lfng dung tinh toan cho cac loai tua bin co chiSu cao kh^c va dir^c lip d$t t^i cac vOng co m$l set khac tren lanh thd Viet Nam Khi so sanh k4l qui tinh toan vol phuvng phap lEC, ta nhan thiy s6 lin set dinh vao tua bin gio xac dinh theo phirang phap EGM lan han phuvng phip lEC dac biet vdi cac tuabin c6 chieu cao tong lan tren 110 m va khu vi/c co mat set lan Dieu dd gai y rang phuxmg phap EGM nen duac su" diing di xac dinh s6 ikn set danh vao tua bin cho cac tinh to^n bao ve chong set TLF khoa: EGM, lEC, chdng set Abstract This paper introduces a method based on the Electro-Geometncal-Method (EGM) to determine the number of direct lightning strikes on a wind turbine considenng the change of blade height due to rotation Different types of turbine installed in areas with vanous flash densities in Vietnam were used to compute the number of stroke When comparing with lEC method, it was shown that the number of direct stroke to wind turbines determined by EGM method is higher than that determined by lEC, especially for the wind turbines higher than 110 m and areas with high flash density Thus, it is suggested that EGM method should be used to determine the number of direct stroke to wind turbines for lightning protection purposes Keywords: EGM, lEC, lightning protection l D ^ t v ^ n de Nhfing nam gan dSy, cong nghe dien gio lien tuc dupe phat trieo ca ve cong suat va kich thuo-c (hinh 1) [i],pi ., j^rTl-'v Hinh Tinh hinh phat trien cong nghe tua bin gio the giai [I] Dien gio da duac trien khai lap dat, van hanh va dong gop phan dien nang quan trong viec phat trien nen kinh te tai nhieu quoc gia tren toan the gioi, CO Viet Nam Cac tua bin gio thuang dugc lap dat a dja hinh cao, trai nen kha nang bi hu hong set danh ' Dia chi lien he: Tel: 04,3869.2009 Email: top.tranvan@hust edu.vn rat cao De chii dong vifc bao ve chong set cho tua bin gio, ta can xac dinh dupe so lan set danh true tiep trung binh hang nam Viec xac dinh so lan set danh true tiep doi v6i cac cong trinh tinh tren mat dat nhu duang day truyen tai dien da tuong doi ro rang [3]-[6], Tuy nhien, doi voi cong trinh dong, co chieu cao luon thay doi ph^l thupc vao vi tri cac canh quay nhu tua bin gio thi can phai dupe xem xet danh gia Bai viet se giai thieu m6t phuang phap xac dinh so lan set danh trirc tiep tua bin gio xet den sir thay doi dp cao theo vi tri quay cua cac canh tren ca sa mo hinh dien hinh hpc (EGM) [10] Phuang phap se duac ling dung de tinh toan so lan set danh trirc fiep trung binh nam cho mpt so loai tua bin gio c6 dai cong suat tir vai tram kW den vai M W (img vai dp cao khac nhau) lap dat tai viing co mat dp giong set khac tren lanh tho Vi^t Nam M o hinh di^n hinh hoc Mo hinh dien hinh hpc dupe C F Wagner dc xuat diiu tien vao nam 1961 [4], sau duac nhieu tac gia nghien cihi phat trien d l danh gia hieu qua bao ve bang cpl t h u s e t hoac day thu set ciia cac cong trinh dudi mat dk nhu- ducmg day tai dien, tram biSn Taip chi Khoa ht^c vi Cong nghe 102 (2014) 012-016 tich thu hilt set la hinh tron co ban kinh r xac dinh theo hai dieu kien: -Khih>pS(hayI< Ic): r-S^IO.I''-*^ (5) - Khi h < ps (hay > Ic): r = ^IpSh-h' + S^l-p-) (6) do- Ic la dong dien giai ban xac dinh theo cong thiic: Hinh Mo hinh dien hinh hoc Dua tren cac nghien ciiu thuc nghiem, doi vai cong trinh tren mat dat co cao h, cac nha khoa hpc da xac dinh dupe khoang each phong dien set vao cong trinh hoac xuong viing mat dat xung quanh cong trinh Vi tri phong dien set (xuong cong trinh hay xuong dat) phu thupc vao tien dao xuat phat tir dam may giong Khi tia tien dao xuit hien vimg BC thi se ph6ng dien vao cong trinh; tia tien dao xuat hien vimg AB hoac CD se phong dien xuong dat {hinh 2) Khoang each phong dien vao cong trinh S va khoang each phong difn xuong dat Sg phu thupc vao tri so dong dien set I [4, 5]: S^AI" (1) Sg^PS (2) ITNG DVNG MO HINH DifN HINH HOC XAC DINH SO LAN SET DANH TUA BIN GIO Theo cac thiet ke hien nay, dau thu set dupe gan tren canh tua bin gio {gia thiet co ten A, B, C) each deu khong gian mot goc 2n/3 Khi lam viec, cac canh tua bin lien Uic quay nen co the coi dien tich thu set ciia dau thu set gan tren cac canh la mpt hinh chii nhat co chieu rpng w bien thien phu thuoc vao vi tri quay ciia canh Viec coi dien tich thu hiit set ciia tua bin gio la mpt hinh chii nhat la vi set danh vao bat cii vj tri nao ciia tua bin canh dang quay (giira cac canh hoac vao than cot tru) ciing la danh vao tua bin Neu goi goc lech giiia canh A vai true hoanh qua tam cua ba canh la 0A (hinh 3) thi ta CO the tinh duac- h-ong do: A, b va p la cac hp s6 Cac tac gia khac dua cac he so A, b va p khac nhau, Tuy nhien, theo nhom lam viec ciia IEEE [6]_khuy6n nghi va dtrpc IEEE Std 1243-1997 [7] chap thuan lay A = 10; b = 0,65; p co tri s6 bi8n thien phu thupc vao dp cao h cua cong trinh theo congthiic [7]: p = 0,36 + 0,17In(43-h) (3) vdi h la chieu cao cong trinh (tinh bang m), neu h > 40m thi lay h = 40m Vi tua bin gio hien dai thuong CO chieu cao Itm ban 40m nen co the tinh duac p = 0,547 Thay tri so A, b tren vao (I) ta duac khoang each phong dipn vao cong trinh xac dinh theo cong thiic; S-lO.lf'^^ (4) vdi S tinh bang m, I tinh bang kA Theo mo hinh dien hinh hoc, cong trinh tren mat dat CO dp cao h se thu hiit cac phong di?n set tren dien Hinh Dien tich thu set ciia tua bin gio phu thupc vi tri cac canh [10] T^p chi Khoa IIQC va Cong ngh| 102 (2014) 012-016 - ChiSu rpng hinh chii nhat thu set: H