NGHIEN CLfU - TRAO D 6 |
MOT S6 KfiT QUA NGHIEN CUU, TINH TOAN VA THI^T Ki. BO VAN DliU KHI^N OlfiU T 6 C
TRONG N H A M A Y T H O Y DIEN 100 MW
SOME RESEARCH RESULTS, CALCULATION AND DESIGN FOR UNITS OF CONTROL'"
VALVE OF SPEED CONTROLLER IN HYDROPOWER PLANT 100 MW ThS. Phan H&u Thang, KS. Bao Thidn Nghia
Vidn Nghidn cuu Ca khi, Bd Cdng Thuorng TOM TAT
Bdi bdo gi&i thieu torn tdt cong dung, tinh ndng ca bdn cua bo van dieu khiin dieu tie, mgt cum thiit bi quan trong trong nhd mdy thiiy dien, co cong suat khodng 100 MW. Noi dung chinh cua bdi bdo de cdp den tinh todn, vgt lieu vd thiet ke bq van ndy. Cdc ket qud nghien cim se dupe dp dung trong thuc te tgi cdc nhd mdy thuy dien co cong sudt to mdy 100 MW.
Tir khoa; Tinh todn, thiet ki; Bg van dieu khien diiu tSc; Nhd mdy thiiy dien.
ABSTRACT
This paper briefly introduced the use, basic features of the speed control valve, a cluster of importance equipment in hydropower plants with a capacity of about 100 MW. The main conteni of the article refers to the calculation, materials and design of this valve. The research results will be applied inprgctice at the hydropower plants with a capacity of 100 MW units.
Keywords: Calculation, Design; Unit of control valve of speed controller; Hydropowerphmi
1. DAT VAN DE djnh t^ong thoi gian dai.
Hien nay, d Viet Nam he thdng cac nha Mdt hong cac hd thdng thidt bi chhih cua m^ay thuy dien cd mdt vai trd quan hong cung nhi may thuj- didn Ik hd thdng thuy luc diSu cap mot sau luomg nang luong khdng nhd khidn canh hudng nuac toa bm. Bay la thidt bi khong ch, phuc vu dan sinh, cdng nghidp, ndng vin cdn dang duac sir dung rdng rai hong cac nghiep ma no con cd vai trd ddng gdp vao an rfia may thuy dien cd cdng suit Idn hen thi nmh nang luong quoc gia. Tuabin thuy luc la gidi vdi cac mi didm vd traydn ddng nhu lam mpt bp phan quan trpng nhat hong nha may viec em, chiu tai trong ddng tdt. d cac nude oSn i l c d r ; , ! ? \ > ^ ' ° ' . " ' ' ' °* '"'^^' °^'' ^ » S •'*idp phat tridn, vide nghien eta, ^ c d t c S f r , ' • ^ ' " ' ' * * ' ' ' tinhtoan,thidtk"achdtaobdvandidukhiSn toarrMnM- ' . " ? i " ' " ' ™ " ' ' ' ^ ' ' ™ ' 4iSutdckdcanghiencfavatIidu,chdddcdng taabmdo,hoiphaicodpbencao,vlnhanhdn nghe va thidt bi kidm tra da rit h^an chmh va
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NGHIEN CU'U-TR^ui^'U!
da dat den do dn dinh, tien tidn hidn d^. Bd phan nay cung la thidt bi dac chung, vi d Vi$t Nam hien nay chua cd co sd ndo nghien ciiu fliidt ke va che tao thidt bi nay, vdn phai dat hang mua thidt bi tu nuac ngoai vdi gia trj cao.
Bg van dieu khien dieu tdc chinh la he flidng didu khidn bdng thuy lire co ciu tao la bg ddi pitdng - xy lanh sieu chinh xdc, tioh nang tmyen ddng uu vidt, 1dm viec em, chiu tai trgng dgng tdt, do bdn cao,... dugc dung nhidu Uong cac ngdnh Cdng nghidp, trong cdc h6 thdng ddng md ciia nhieu thiet bi khdc nhau, dac biet trong cac nhd mdy thiiy dien [1]. Hidn nay, cdc nha mdy dien van phai dat hang mua bd van nay tu nude ngodi vdi gia tri cao. Nhu _vay, vua anh hudng ddn kinh td va viia khdng dhi: dgng duac trong viec thay the, sura chiia thidt bi cua nha may. Hinh 1, dudi day Id so dd vi tti dieu khien canh hudng ciia secver moto Nha may Thiiy dien Hda Binh [4].
ciia secvomotor se qua h$ thdng thanh truydn gdn vdi vanh didu chinh, giiia canh hudng va v^ih didu chinh cd cac khdp truydn ddng.
Ngay nay, vdi sir phat tridn vugrt bac cua ky thuat sd, bd didu tdc tuabin dugc tu dgng hod hodn toan cd kha nang tiiu thap cac thdng sd qud trinh mOt each Udn tuc, hr dgng dieu chinh dn dinh trong qud trinh v ^ hdnh. Bd didu tdc tuabm gdm bd dieu tdc ky thuat sd va bO dieu tdc thuy luc.
2.1. Cac tinh nang dilu khiin va di^u chinh tdc do [2]
Didu khidn vi tri: Sii dung thuat toan didu chinh PD, tin higu vao la vi tri thuc cua cdnh hudng va viing trugt cua cac servomotor.
Khi van hanh d che do qua tdi, su gidi ban tdc do ciia canh hudng vd b^ih cdng tac duac dat len hang dau nham Uanh tuabin lech khdi vi tri tdi uu.
Hinh 1. Vi tri dieu khiin cdnh hu&ng secvermoto Nhd mdy Thuy di$n Hda Binh
Bdi bao tap trung trinh bay cdc kdt qud nghien cuu, ca sd tinh todn va cdng nghd chd tao bd van dieu khidn dieu tdc nay.
2. CAC D^C TINH VA T H 6 N G SO KY THU^T B O VAN D I E U KHIEN DIEU TOC
Dd didu chinh dd md canh hudng, sii dung cac secvomotor (d day Id 4 servomotor theo Hinh 1) vd he thdng thuy luc. Truyen ddng
Dieu khidn gidi han do md: Do md gidi han cd the duac dieu chinh trong khoang -5 ddn 105 %.
Dieu Idiidn vdn tdc: Sii dung thuat todn dieu chinh PID cd phdn hdi, gia tri dat c^a bd dieu khien van tdc cd thd dugc diSu chinh trong khoang 90 den 110%. Dai tin sd chdt cd' tdc dung trong sudt qud trinh van hdnh song song vd cd thd didu chinh dugc. Bd didu chinh PID se xdc dinh didm dat cho servomotor vd tdc dd thuc td.
Dieu khidn do md canh huong: Gia tri dat cd the dugc dieu chinh trong khodng -5 ddn 105%, che do vdn hdnh ciia bd didu khidn nay chi cd the dugc lua chgn khi td may vdn hdnh d chd do song song, trong cac chd do khac didm dat cua do md se Id do md Ihirc ciia canh huong.
Didu khidn luu lugng: Gia tri dat cd thd'^
f%^^
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NGHIEN CU'U - TRAO B O I
duac didu chinh trong khoang -5 ddn 105%.
Luu lupog thuc td dugtc tinh toan hi cdt nude, v5n tdc tuabin, vi tri cua canh hudng v4 bdnh cdng tac. Bd didu khidn sil dung thuSt toan PI, xac dinh gia tri d^t cho vi tri cua servomotor canh hudng bSng each tinh toan su khac nhau giiia gia hi dat va lini lupng thuc td. Ham B^ydn cua bd didu khidn cd dang:
Bidu khidn muc nude: Gia tri didm dat dd duoc xac dinh trade, nd chi cd thd dupe x4c dinh lai thdng qua cdc thidt bi diu cudi, bang van hanh hay giao didn thdng tin. Bd didu khidn sur dung thuat toan PI.
2.2. Mot s6 thdng so va cic tinh nang ta ddng hoa, dac tinh Ity thuat cua bd d i k tdc [4]
Tren co sd cac mlu khio sat d Thiiy didn Hda Bmh va Tri An, chpn cic thdng sd va cac tinh nang tu ddng hoa, dac tinh ky thuat cua bd dieu tdc nhu dudi day,
Cdc thong so:
Chuin giao didn: RS232, RS485, Ethernet;
- Dai tdc do chdt: £ 0.02%; Thdi gian chdt: £ 0.2s;
- Dai tin sd do dupe dmg vdi tdc dp; 1,2 ddn lOOOOHz;
- Dp dn dhih tdc dp; £ 0.3%; Dp dn dinh cdng suit: £ 0.4%;
- Thdi gian tich phan Tn: 0.05 ddn 5000s;
Thdi gian vi phan Td: 0 ddn 10s;
- Do ddc ciia dac tinh tdc dp bp: 0 ddn 10
%; Hd sd ty Id Kp: 0.500;
- Thdi gian md canh hudng cd thd didu chinh: 10 ddn 1000s.
todcuabpOiuldc:
- Dieu chinh vi hi cac canh hudng ddng bd vdi banh cdng tic;
- Giam sit va kidm tra tdc dp, Imi lupng;
Bieu chinh vide chpn nhanh miic tai;
- Van hanh da nhidm theo (hdi gian thirc; Giao didn Ethernet chuin vdi hd thdng SCADA;
- Giao didn HMI tai phdng didu khidn va to dieu khidn tai chd;
- Bio v? didn mdt chik cic Module I/O, kidm tra cao tin hd thdng.
Bac tinh ky thuit cua he thdng van didu khien didu tdc:
- Budng kinh lam vide danh nghia cda xi lanh sec vd md to: cl>500mm;
- Hanh trinh cua pitton secvomoto: S = 730 mm; Ap suit diu lam vide: P = 40 kG/cm^;
- Luc tic dimg dmh miic: Khi ddng = 37,8x10' kG; Khi md = 78,5x10= kG.
- Thd hch diu hong secvomotor: 0,144 m'.
Cdc dieu kien Idm vi^c cua bo van dieu khien dieu toe nhu sau:
- Ap suit diu lam vide: 40 kG/cm^; Ap suit khdi ddng bom chmh: 37 kG/cm^;
- Ap suit khdi dpng bom du phdng: 35 kG/cm2; Ap suit dung su cd: 29 kG/cm^;
- Ap suit tic dpng md van an toin: Bat diu md 40,5 35 kG/cm^ va md hoan toan d 42 35 kG/cm'; Chu k^ ddng md: Lien tac;
- Mile diu trong bmh ip luc: 35%; Miic diu dftng su cd: 20%.
3. TENH TOAN CO BAN VA THIET KE BO VAN D i i u KHIEN
3.1. Tinh toan [5], |6]
3.1.1. Cdc yen ciu
Vdi didu kien lam vide nhu tren va qua thdng sd khao sat thuc td nhdm dd tai lua chpn mdi ghep giiia pit tdng vi xy lanh la mdi ghdp:
H6/g5.
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NGHIEN CUU - TF^v^ i^wi
Theo sa dd hoat dgng ciia bd van dieu khien didu tdc chinh thi bg phan xy lanh se la bg phan dung yen, cdn bd phdn pit tdng se Id bd phdn chi^en d^ng tinh tien trong xy lanh.
Vdi dieu kien hoat ddng nhu v^y, bd mat 1dm viec giiia hai chi tidt chi la be mat Ir^i trong cua xy lanh va be mat tru ngodi cua pit tdng.
Dd dam bdo bd van hoat dgng dugc dn dinh cd tudi ben cao thi ydu'cdu do ddng bO giiia xi lanh vd pit tdng cao. Ydu cau dd tnj, do trdn bd mgt 1dm vide cuaxi lanh - pit tdng cd do chinh xac cao se dugc the hidn cu thd trong bMi ve chi tidt.
Vdi ydu cau siia chiia thay thi; hoat ddng dn dinh theo bd ddi, nen ydu cau cdc be mat lam vi$c cua xi lanh - pit tdng phdi cd do Cling tuong duong de ddm bao cd thdi gian hogt ddng ddng ddu.
Xy lanh cua bd van didu tdc dugc cd dinh tren than vd hai dau se cd cdc Id bat cdc mat bich hd de thoat dau.
Tren th&i xy lanh cd cac mat tru dinh vi de cd dinh vi tri xy lanh bao gdm cdc mat tru O 205 vd 0210. Vi la mat tru dinh vi n8n cac mat tru ndy yeu cau gia cdng ddng nhSt dam bdo do chinh xac vai cac mat trii trong.
Pit tdng trong he didng van vd bd phdn chuyen ddng dugc gdn vdi ca cau con quay ldc dieu chinh nhd vao cac can dieu chinh, vi vay tren ddu pit tdng cd cac Id de lap rap.
Than pit tdng chi cd khodng lam viec tai hai ranh ddu hai ddu xi lanh nen phan than tru lam viec ciia pit tdng chi dugc gia cdng d hai ddu.
3.1.2. Tinh todn chiiu d^ thdnh xi lanh vd duotng kinhpittong nho nhat
van didu khidn didu tdc chinh ta cdn tinh todn bd ddy thdnh xi lanh vd dudng kinh pit tdng nhd nhat nhu sau:
Bdi toan tmh toan do day cua vd xi lanh dugc md ta nhu Hinh 2:
Theo thuydt bdn iing suat tidp Idn nhat, vd xi Janh chiu cdc thdnh phan ling sudt tiep tuydn va bai todn d ddy Id tinh todn sao cho vd xi lanh du ddy de chiu dugc ap sudt tdi da cua he thdng khi lam vide va ap suat thii theo nhu quy dinh vd tidu chuin xi lanh, ta cd cac tri sd ling suit umg sudt ciia vd xi lanh kiii chiu tdi:
pa I I 2 il
(b -a ) r (0 -a) r Trong dd:
a^ va Ogi La cac ling suat tiep tuyen quy theo he triic toa dg tri^ (G, r);
p: Ld dp sudt max ciia xi lanh (Idy bang dp suit thur 60kG/cm^);
a: Dugng kinhtrong cua xi lanh Ion nhat (154 mm);
b: Dudng kinh ngodi cua xi lanh.
Diem nguy hiem la diem bdn trong, tai do r - a. Khi do, cac thanh phan iing sudt Id:
Didu kidn ben theo thuydt bdn iing suit tiep Idn nhat Id:
o —a
Trong do: [o] Id ung sudt chay deo cho phep cua vdt lieu thep 30XM (theo rOCT).
Dd xay dung kich thudc sa bd cua bd
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NGHIEN ciiu-TRAO D 6 |
Hinh 2. Sa do tinh todn chieu diiy vdxi lanh [a]-^ 53,1 kN/cm'
Bien ddi bat phuong trinh tren vdi i n sd b, ta dupe:
b>203,32mm
Nhu vay, chidu day xi lanh tdi thidu la:
h = (b-a)/2 = 24,66mm
Bai toin tinh toan dudng kmh pit tdng dupe md t i nhu Hmh 3:
Vdi ducmg kinh xiTanh Idmnhitla 150 mm (15 cm) thi dien tich cua piston la:
Gpi luc dieu khidn canh hudng ciia xi lanh l i F, bang g i i h i luc gay ra do i p luc diu, luc nay dat g i i h i Idn n h i t frong chd dp thu bp van didu khidn vdi ap suit la p = 60 kG/cml
Vdi dudng kinh xi lanh Idn nhit la 150 mm (15 cm) thi didn tich ciia piston la:
S = 9tDV4 = 3,14.15V4 = 176.6 cm^
Luc tic dung dupe tinh la:
F = S.p = 176.6x60 = 10,6.10^ kG = 1 0 6 . 1 0 ' N = 106 kN
Gpi A la dien tich tidt dien cua cin di6n khien secvomotor. Theo ly thuydt vd siic bSn vat Ueu: Vdi vat lieu 30X13, cd ling suit bdn cho phep l i : [o] = 41,6 kN/cm^
T a c d : F l / A < [a] -^ A>Kl/[a]; A>
106 (kN)xl,5/41,6 = 3,8 cm^
1: L i he sd tinh ddn su 6n dinh ciia pit tdng, 1 = 1 , 5 .
Vay, dudng kinh nhd nhit ciia pit tdn cin thiet la:
Vay, ijicin > 4,85 cm = 48,5 mm.
HinkS.Sa do tinh todn duang kinh pit Gpi Ijrc didu khiin cinh hudng ciia xi lanh la F, bSng gia fri luc gay ra do i p luc diu, luc nay dat gii trj Idn nhit frong chS dp thu bd van didu khidn vdi i p suit la p = 60 kG/cml
3.1.3. Bieu kien Idm viec va lua chon vdt lilu cua bo van diiu khiin dieu tic chinh
Van thiiy luc didu tdc chmh la thidt bi rat quan hong, lam viec lien tac, vdi hai bp phan chinh la xi lanh van va piston van.
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NGHIEN CU'U - TRAO DOI
Chinh vi v^y, rdt cdn phai chgn vdt lieu phu hgrp vdi kdt cdu va dap ling dugc kha nang lam vide cua thidt bi. D\ra tren vide phdn tich thanh phdn, ca tinh cua tiing loai vat Hdu chd tao thuang su dung cho thidt bi xi lanh vd pit
lieu che tao bg ddi, nhu sau:
Vdt lieu chd tao xi lanh la thep 30XM - rOCT 4543-71 vai thdnh phdn theo phdn tram cac nguyen td hda hgc chinh vd ca tinh lihu tdng thdng dung, nhdm dd tai da lira chgn vat Bang 1 va Bdng 2 sau:
Bdng 1. Thdnh phdn cdc nguyen to hoa hoc chinh 30XM, %
c
0.26 - 0.34 Si 0.17-0.37
Mn 0.4-0.7
Cr 0.8-1.1
P
<0.035 S
<0.035
Mo 1
0.15-0.25 1Bang 2. Co tinh vdt lieu che tgo 30XM:
Gidi han ben, MPa
531
0$ dai va d^p, J 23
Bd dan d^i,
% 22
B9 thit,
% 24 Dd gia tang do ciing trong Idng xy lanh, sii dung phuang phap thdm Nito.
Vat lieu chd tao Pit tdng la thdp 30X13 - TOCT 4543-71 vdi thanh phdn theo p h k tram cac nguyen td hda hgc chinh va ca tinh nhu Bang 3 vd Bdng 4 sau:
Bdng 3. Thdnh phdn cdc nguyin to hoa hoc chinh 30X13, %
c
0.26-0.35 Si
<0.8
Mn 1 Cr
<0.8 12-14 P
<0.03 , S
<0.025 1 Ni
<0.6 Ti
<0.2 Bdng 4. Ca tinh vgt lieu che tgo 30X13:
Gidi ban ben, MPa
416
Gidi ban chay, MPa
439
B6 dai va dfp, J 13
Do dan dai,
% 13
1 S9 tbSt,
% 1 14 De tang dg cung be mat pit tdng, su dung
phuang phap tdi cao tdn cdc bd mat idm viec.
3.2. Thiet ke cum pittong, xi lanh
Thiet ke ban ve xi lanh:
Ehidfng kinh Idng xy lanh, dugc ky hieu la d: Xac dmh luc Idn nhat dudi dp suit lam
vide cho truoc, xy lanh thiiy luc tao ra dugc luc lam vide tren cd hdnh trinh lam vide ciia nd (tiic Id khdng phu thudc vdo vi tri ciia qua pis- ton) khi ap sudt cdp vao khoaig 1dm viec vdn du nhu thiet ke. Luc ma sat giua qud piston/
vdng kin vdi long xy lanh hoac luc udn cdn xy lanh do viec lap rdp xy lanh khdng dung each se lam gidm lire ddy/keo cua xy lanh.
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NGHIEN cuu-TRAO 06l
Dudng kinh long xi lanh van didu khidn didu tdc chinh dugc xdc dinh do luc qua vang trong bd didu khidn tac dgng. Nhdm de tai thuc hidn khdo sat Idy mdu xic dinh thdng sd dudng kinh trong ciia xi lanh b0 van dieu khi6n didu tdc chinh Id 150 mm vdi ddu Idn vd 142 mm vdi dau nhd.
Dung sai kich thudc lap dat vdi dudng kinh trong xi lanh nhu da trinh bay trong ngi dung tren Id H6 vdi dung sai cu thd nhu sau:
Vcd kich thudc ddu Idn 150 nun, dung sai tren Id +0.025 mm, dung sai dual la - 0 mm.
Vdi kich thudc diu Idn 142 mm, dung sai trdn la +0.025 nun, dung sai dudi la - 0 mm.
Be day tdi thidu xi lanh da xdc dinh trong ndi dung tren Id 24,66 mm vdi thdng sd khao sat dugc be ddy xi lanh nhd nhdt Id 27 mm dam bdo yen can.
Kich thudc ngoai cua xi lanh Id kich thudc lap rap vdi khung vd la cdc mat tru $ 205 va $ 210 cd chd dd ldp rap la H7/h6 vdi dung sai cu thd nhu sau:
Vdi kich thudc ddu Idn O 210 mm, dung sai tren la + 0 rrun, dung sai dudi Id-0.029 mm.
Vdi kich thudc ddu Idn 0 205 mm, dung sai tren Id + 0 mm, dung sai dudi id-0.029 mm.
Bdn ve che tao xi lanh dugc md td nhu Hmh 4 dudi.
Hinh 4. Bdn ve chi tiet xi lanh
Hinh 5. Bdn ve chi tiet pit tong Thiet ke ban ve pit tdng:
Qua qud trinh nghidn ciiu, tim hidu nhan thay pit tdng cd hai bd mat 1dm viec quan trgng tiuydn ddng trugt chinh trong bd mat tru trong cua xi lanh Id bd m^t truO142vd<l>150.
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NGHIEN CU'U-TRAODOi
Dung sai hai bd mat tr^ nay dugc xac dinh trong ndi dung tren la chd do lap h5 vdi dung sai cu the nhu sau:
Kich thudc be mat tru (5142 cd dung sai kich thudc trdn Id: -0.014 mm; dung sai kich thudc dudi la: -0.032 mm; Kich thudc bd mat tru O150 cd dung sai kich thudc trdn la: -0.014 mm; Dung sai kich thudc dudi la: -0.032 mm.
Khoang each giiia hai mat tru 1dm vide cua pit tdng Id khoang cdch quan trgng quydt dinh viec ddng md cac Id thodt ddu trdn thdn xi lanh ndn ydu cdu gia cdng chinh xdc, theo kdt qua khao sat thuc nghiem khodng each ndy la:
229,2 mm vdi dung sai kich thudc Id: -0.05 mm.
Bdn ve chd tao pit tdng dugc md ta nhu Hinh 5 Uen.
4. K£T QUA VA DE X U A T
Vdi ket qua da nghien ciiu, iihdn thay trong didu kien cdng nghe va thidt bi hien nay d Viet Nam chung ta hoan todn cd thd lam chu viec nghien cuu, tinh todn, thidt kd, chgn vat hdu va cdng chd tao bd van didu khidn didu tdc nha mdy thiiy dien cd cdng sudt td may din 100 MW, ddn cd thd thay thd nhdp ngoai cum van nay vdi gia thanh thdp va chit lugng tuang duong nhdp ngoai.
Thdi gian tdi, trudc mit dd nghj bd van nay dugc dua vao chay khdo nghidm, danh gia tinh nang tai cac may thuy didn cdng suat td may 100 MW vd lam co sd ddn tidn tdi hodn chinh cdng nghd de chd t^o thanh san phdm ndi dia hoa, thay the nhap khau.<*
Ngay nhdn bai: 12/01/2017 Ngdy phan bidn: 10/02/2017 Tai lidu tham khao:
[11- Nguyin Phu Vjnh; Mdy thuy luc vd truyin dong thuy lycc - NXB. Dai hgc Bach Khoa, Ha Ndi, 1979.
[2]. V5 Sy Huynh, Nguyin Thi Xuan Thu; Tua bin nu&c, Khoa hgc Ky thuat. Ha Ngi (2005).
[3]. Nguyin Thanh Tri; He thdng thuy luc, NXB.
Da Nlng (2006).
[4]. Tai Ueu khao sat cdc nha may Ihiiy di$n Hda Bmh, Tri An, Nhdm D6 tai thuc hien.
Ha Ngi, 2016.
[5]. Dinh Ngpc Ai; Cong nghi chi tgo mdy thuy khi, NXB. Dai hgc Bach Khoa, Ha Ngi (1977).
[6]. Nguyin Van Vugng; Ly thuyit ddn hoi img dung, NXB. Giao diic, Ha Ngi (1999).
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