Tuyen tap bao cao khoa hgc Hdi nghi Khoa hoc ky thudt Do lirdng toan qud'c lan thur IV Hd Ngi, 11-2005 v/MO HINH TINH TOAN TRUT Ll/ONG GrO PHUC VU QUY HOACH N H A MAY DIEN sCr DUNG NANG Ll/ONG Gl6 Trdn Hodi Linh Bd mdn Ky thudt vd Tin hgc cdng nghiep Trudng Dgi hgc Bdch khoa Hd Ngi Tdm tdt: Nhd vdo tinh "sach" cua minh md ndng lugng gid la mgt ngudn ndng lugng dang dugc quan tdm hiin Tuy nhiin viic xdc dinh vi tri xdy dung mgt nhiing vdn de ddu tien cdn dugc gidi quyit quy hogch nhd mdy dien gid Tuoi thg cua mdt nhd mdy diin gid thudng khong qud ddi, dd viic tinh todn trd lugng gid cua diim dgt yiu cdu dd chinh xdc cao Do dd mgt nhiing gidi phdp hien Id tiin hdnh quan trdc thdi gian ddi di thdng ke trd lugng dugc chinh xdc Trong bdi bdo ndy tdc gid se trinh bdy ve mgt md hinh tinh todn trd lugng gid tgi mdt vi tri dua vdo cdc kit qud quan trac td nhdng vi tri xung quanh Md hinh tinh todn ndy cd dd chinh xdc cao vd thdi gian cdn thuc titgi diim ddt nhd mdy ngdn han so vdi cdc phuang phdp thdng thudng Abstract: Wind energy is one type of "clean " energy resources that recently has attract quite a lots of interests Determining the optimum location is one of the first issues that need to be addressed in planning wind turbine plants The time in use of a wind turbine plant is normally not too long Therefore the calculation of the wind energy reserve at wind turbine site requires high level of accuracy One of the solutions is to measure the wind energy reserve in a long period of time to obtain accurate statistical data In this article, the author will present a model to calculate wind energy reserve at a certain location based on measurement data from other location near-by This model has high level of accuracy and the timing for actual measurement at the plant site is shorter than other common methods I Gl6l THIEU CHUNG Viec xac dinh dilm ddt nhd may dien gid la mOt nhiJng nhiem vu quan trgng phai xdc dinh trudc tien bdt ddu quy hoach nhd mdy dien Dl tinh todn dugc trd lugng gid cija mdt dilm dat ta edn phai cd sd lieu vl tdc d6 gid tai vi tn mOt khoang thdi gian dii dai dl cd thi dua cdc kit qua tinh todn chmh xdc vi thdng thudng tudi thg cua mdt nhd mdy dien gid khdng qua cao Tuy nhien viec dac dai han tai mdt vi tri se keo dai thdi gian ti'nh toan cung nhu lam chdm tiln dd eiia viec xdy dung Trong bai bao nay, tac gia se trinh bay vl phuong phdp siJr dung cdc kit qua tugng tai cac dilm Idn cdn va xdy dung md hinh tinh xdp xi mdi lien he giiJa tdc dd gid tai vi tri khao sat vdi cac dilm Idn cdn Viec sir dung md hinh dua lai kit qua cd dd chinh xac eao va ed thi giam thdi gian dac 359 II PHUDNG P H A P T I N H TOAN De xdc dinh dugc kha nang san xudt nang lugng gifi tai mflt vj trf A ta cdn cfl dugc bieu van tflc gifi W^lt) tai diem dat theo thfli gian Vfli cdu lao c i a cac tufl'c bin hien thi cac luflng gifl vfli tfic giao dgng khoang t i dfin 25m/s mfli cfl th^ s i dung duoc nhu cfl the thiy trfin hinh tflc dfl gifl cham se khflng d i de van hanh may u phu thuoc cong suat phat aua turbine Sr 400 Van toe QIO (m/s) Hinh Bieu cong suat ciia mot turbin gio phu thugc vao tdc gio phdt, edn tdc dd gid qud cao se gdy md't an toan co hgc eho may phat TiJr van tdc gid 'Wf.ii) ta c6 thi dl dang xde dinh c6ng sud't phdt ciia nhd may P(t) theo thdi gian De cd dugc bilu dd vdn tdc gid thdng Ihudng ta phai tiln hanh dac mdt thdi gian ddi (thudng Id vdi nam) dl cd thi dua dugc mdt md hinh xd'p xi D6 chinh xac ciia m6 hinh c6 y nghTa ddc biet quan trgng vi tudi thg cua m6t nha may phat dien nang lugng gid thudng khfing cao so vdi thdi gian hoan vdn diiu kien lam viec binh thudng Nhung ta ciing thd'y rdng viSc tiln hanh dac nhilu nam se ddn tdi viec phai chd dgi dai, nhd't Id trudng hgp cdc dilm dugc lua chgn ban ddu lai khdng ddp dng dugc ySu eau ky thuat cua nha mdy (vi du nhu gid qua manh, phdn bd khdng diu, ) D l khdc phuc dugc nhugc dilm ndy ta cdn phai lim dugc giai phap rut ngdn dugc thdi gian dae Trong bai bao tac gia da xay dung md hinh dua trSn cde sd lieu dac quan trdc tai ede dilm Idn cdn gdn vdi vi trf lua chgn Trong thuc t l m6i vCing ta thudng cd cdc dilm thu thdp sd lieu quan trdc tucmg lien tuc mdt thdi gian ddi (cd the tdi hang chuc ndm) Khi cdn xac dinh trd lugng va bilu dd tdc d6 gio W^(t) tai mdt dilm A, trudc tien la xdc dinh dilm Idn cdn (vi du nhu B) md tai dd ta cd cac sd lieu quan trdc dai ban WB(t) Nlu nhu la cd dugc mdi quan he phu thu6c giOa tdc d6 gid cua hai dilm Ihi ta ed thi de dang tinh dugc vdn tdc gid lai dilm A Irong toan bd khoang thdi gian ta da d B D l xdc dinh dugc mdi quan he phu thudc ta se tien hdnh dac tai diem A Irong mdt khoang thdi gian ngdn (thudng Id td thdng eho tdi I nam) Trong thdi gian ndy, ta vdn cd cac sd lieu dac tai B T£r nhirng sd lieu ta se xdy dung mdt ham phu thudc gida luu lugng gid tai A vao luu lugng gio tai B Sd dung hdm phu thudc ndy cho tdan bd thdi gian da dae tai B ta se cd dugc kit qua gdn dung eho luu lugng gid lai A thdi gian dai Tuy nhien cac thi 360 nghiem thuc tfi cho thdy cdc ham phu thufic ndy la cdc hdm phi tuyfin bdc cao, hon ntta cdc stf lieu dac lai chtta nhifiu nhifiu, vi vdy dfi khdc phuc cdc yfiu difim tren, tac gid da lua chgn mfi hinh xdp xl id cdc mang ng-rfin Mang no-rfin cfi kha ndng thich nghi vfli stf lifiu theo quy tdc hgc [1,2,5] dfi viec xay dung mfi hinh se trfl nfin don gian hon vi nhifim vu tinh todn cfi thfi dugc thuc hifin m dfing trfin mdy tinh, ben canh dfi voi cdu trie kfi't ntfi song song mang no-rfin cfln cfl kha nang chfing nhieu tfit, thich hgp cho nhttng bai todn stf lieu nhifiu nhifiu Tdc gia da lua chgn mfi hinh mang kinh difin MLP dfi tinh todn cho bdi todn ndy III MANG MLP VA IJMG DUNG M HINH HOA HAM PHI TUYEN Mang MLP la mflt ttong nhttng mang no-rfln dugc xay dung ddu tien va hifin da dugc ttng dung rit rfing rai ttong thuc tfi [1,5] Cdcttngdung mang MLP ttong cdc vdn dfi ky thudt cfi thfi ke tfli: mfi hinh hfla hdm phi tuyfin, nhdn dang dfl'i tttgng tuyfin tinh, nhan dang dfii mgng phi tuyfin, phdt hifin phdn t i su cfi hay hi sai sfi hfi thfing Mang MLP dugc xdy dung ttt cdc phdn ttt eg bdn ggi la ng-rfin Mfi hinh todn hgc cia mflt ng-rfln dugc ttinh ufin hinh ve 2a MO hinh rut ggn dugc trinh bdy Uen hinh 2b a) b) Hinh Mfi hinh toan hgc cia na-rfin; mo hinh ddy du (a) va rut gon (b) Mfli mflt ng-rfln cfl mflt stf ddu vdo x, Mfii ddu vao tin hifiu x, dttgc khufich dai bang ttgng sfi kfi't nfii W, Cdc tin hifiu ddu vdo dugc liy tfing cfl trgng Iugng vd tao tin hifiu di qua khfii ham/ Ham/dugc ggi Id ham truyfin dat hodc hdm kich boat (activation function) Trong thttc tfi ta thttflng si dung cdc ham kich boat Id hdm: logsig: / ( H ) = 1-i-e"' 11-1-e"' hdm tuyfin tinh: /(«) = au tan hy-pfic-bfl-lic: /(w) Vfii cdc phdn ti ng-rfln co ban ndy, ta cfl thfi xay dung mfl hinh cdu true mang nhifiu Ifiip, bao gfim Iflp ddu vdo X, Iflp ddu Y va mfit sfi Ifip fl gitta ggi Id Iflp dn Tai mfli lfip (trit Iflp ddu vdo) ta cfl cac ng-rfln, gitta hai Iflp cfl cdc kfit nfii cfi ttgng stf Thflng thuflng ta chi cdn si dung ttfi da Iflp dn Id cfl thfi mfl hinh hfla mfit hdm phi tuyfin vfii dfi chinh xdc tiy chgn [1,5] Trong giai phdp cia bai bdo nay, ta se chi ding mflt Iflp dn, dfl mang MLP se gflm cfl tfing cflng Iflp Cduttttcmflt mang MLP vfii Iflp dn dugc thfi hifin trfin hinh vfli W la ma Iran cdc ttgng stf kfit ntfi gitta Iflp ddu vao vd Iflp dn, V la mattdncdc ttgng sfi kfit ntfi gitta Iflp dn vd Iflp ddu 361 Hinh Ciu true mang MLP vfli mfit Iflp dn Cdc ttn hifiu ddu ttt cdc no-rfin thufic Iflp dn se dugc tinh theo cfing thttc; vdi Xg=l dugc ggi Id ddu vao phdn cue (hay edn ggi la ddu vdo hieu chinh - bias), ddc ldp vdi ede gia tri ddu vao khde Tin hieu ddu cua mang se dugc tinh theo edng thdc: /E y,.f\ t.^,^„ Trong qud trinh xay dung mfi hinh ta cdn xdc djnh cdc trgng stf kfi't nfi'i W vd V cho sai stf Id nho nhdt Ta se s i dung thuat todn buflc giam cttc dai dfi giai bdi todn tfii uu phi tuyfi'n ndy [3,4] IV KET QUA TINH T O A N Mang MLP se dugc s i dung dfi xiy dung mfi hinh phu thuflc y=F(x) vfli y Id v6c-to tfic dfi gifl Uong mflt gifi tai difim A vfli khoang cdch 60 phit mflt Idn, x la vec-tO tflc dfl gifl cing thfli difim va thoi difim truflc tai diem B cung dugc vfli khoang each 60 phut mflt Idn (tdc gid dd lua chgn gid trj cufli cung c i a tfic dfl gifl dtta trfin cdc kfit qua thttc nghiem nhdm tang ettflng dfi chflng nhieu cho mfl hinh) Vfli ddu vao va ddu ra, ta lua chgn 16 no-rfin ttong Iflp an Tdc gia cfl 18 thang stf lieu tai vj tri cdn dat Vfii tip hgp nay, ta se chia thdnh hai phdn Mfit phdn ding dfi xdy dung mfi hinh, phdn cfln lai dfi kifim tra dfi chi'nh xac c i a mfi hinh Hinh bieu difin su bifin thifin cua tfic dfi gifl cho 1000 gifl ddu tifin ttong tip hgp xay dung mfi hinh (sfl lieu tai difim cSn tinh todn va tai difim quan udc cfi djnh) 362 (a) Hinh Toe gio dugc tai diem quan trdc cd dinh (a) va diem nghien cdu ddt nha may dien (b) Qua trinh tdi uu hda sai sd bdng phuong phap gradient dugc mo phdng vdi vide six dung thu vien Neural Network Toolbox cua Matlab Hinh cho thd'y qua trinh tdi uu hda da ed thi ket ihiie sau 100 chu ky hgc Sai sd E da giam td gia tri 65,64 tai thdi dilm bdt dau xudng tdi 5,17 ket thuc hgc Sai sd trung binh trSn tdp hgc la l,2m/s s "' WzJM i H—; Id" - ! • i—f- -\ ! ' Hinh Sai so hpc giam dan theo tang sd chu ky hoc Mang MLP thu dugc da dugc kiem tra trtn tdp sd lieu cdn lai Sai sd kilm tra dai l,98m/s Vi du tinh loan bdng mo hinh dugc mo la irSn hinh 6: Dudng gid tri thue leva gid tri xdp xi ciing vdi dudng sai sd dao ddng ehii ylu khoang [-2,2] Ta thay sai sd trtn tdp sd lieu mdi (kh6ng xud't hien qua trinh xay dung m6 hinh) cd the chd'p nhdn dugc, sai sd Irung binh nhd hon 2m/s Cac gia tri cung chdng minh su hoat ddng hidu qua cua mo hinh mang MLP ddi vdi cae trudng hgp "la" chua cd qua trinh xay dung mo binh 363 Hinh Vl du k^'t qua tinh toan so vdi si thuc tg' va sai sd cua mo hinh V KET LUAN Mang MLP da cho phep ta xdc dinh ham phu thudc gida td'e dd gid cua hai dia dilm, tren CO sd dd ta cd thi xac dinh duge tdc dd gid tai m6t vi tri vdi dO chinh xde cao ma khdng cdn phai tiln hanh dae quan trie mOt thdi gian dai Ben eanh dd vdi eac thudt todn hge tu ddng eho phip ta giai bdi todn tdi mi hda mOt each dl ddng vdi cdng eu may tinh Viec dp dung cde giai phap no-rdn la mdt hudng nghidn cdu dung ddn cho phep chdng ta sit dung cdng nghe mdi, dua lai nhdng kit qua ehinh xac Tdi lieu tham khdo: [1] Neural networks, A comprehensive foundation, S Haykin, Macmillan College Publishing Company, 1994, N Y [21 Digital neural networks, S.Y Kung, Prentice Hall, Englewood Cliffs, 1993, N Jersey [31 Neural fuzzy system, C T Lin, C G Lee, Prentice Hall, 1996 [41 Foundation of Neuro-fuzzy systems, D Nauck, F Klaworn, R Kruse, Wiley, 1997 [51 Neural Networks and their Applications, J G Taylor, Wiley, 1996 364 ... chgn mfi hinh xdp xl id cdc mang ng-rfin Mang no-rfin cfi kha ndng thich nghi vfli stf lifiu theo quy tdc hgc [1,2,5] dfi viec xay dung mfi hinh se trfl nfin don gian hon vi nhifim vu tinh todn