Ngo Diic Minh Tgp chi KHOA HOC & CONG NGHE 118(04)-93- 100 NGHIEN c u t ] iTNG DUNG NANG LU'ONG MAT TROI
TRONG CAC MANG filEN CUC BO CUA TAU THUYEN
TS. Ngd Dire Minh
Tnr&ng Dgi hgc Ky thuat Cong nghiep - Dgi hgc Thdi Nguyen TOM TAT
Ndi dung bdi bdo nghign ciru ve dg tai bao ve tdn gid mdi trudng xanh - sach - dep trong vdn de khai thdc vd sti dung ndng iugng tdi tao. Khi dp dung vdi dia bdn tinh Qudng Ninh - Ky quan thign nhien dugc the gidi xgp hang ndm 2012. tdc gid tap trung quan tam dgn van de sii dung he pin Mat trdi cap dien cho. nh&ng cdng trinh ndi tren bien, cd thg Id nhung nhd ndi tai chd hay cdc du thuyen chuyen ddng. Phan ti'ch cdc ygu td lam anh hudng den biic xa Mat trdi ma he pin nhdn dugc bj thay ddi khdc han so vdi trudng hgp he pin ddt tmh tai tren dat lien. De xudt gidi phdp ky thugt phii hgp nhdm dam bdo nhu cdu vd chdt lugng dien nang ciia cdng trinh ddng thai dap iing cdc yeu cau ve mdi tru'dng va thdm my. Xdy dung mdt md hinh mang dien cue bd cd cdu triic PV-MPPT-DC/DC,AC(BESS) trong do cd thuc hien giai phap tdi uu vg ndng tugng cdp ra cua he pin Mat trdi khi cudng dg BXMT nhdn dupc ludn khong dn dinh ke ca khi mdt dot ngot. Ket qua nghien cii'u dugc kiem chung thdng qua cac ket qud md phong bang Matlab/Simulmk
Til' khda: pin Mat trdi, PV-MPPT, PV-LOAD, PV-MPPT-DC/DC.AC(BESS) ..DAT VAN DF
Neu nlui', tir nhii'ng nam 80 ctia the ky 20 ngu'di la xem cdc qud trinh san xuat cdng nghiep hay su phdt trien dd thi hda la nguyen nhdn lac ddng xdu den moi trudng thi gan day, ddc biet budc sang thg ky 21 cdc Nhd khoa hpc da chi rd: chinh cdc qud trinh sdn xudt vd truyen ldi dien ndng Igi la tac nhdn nguy higm hon ddn dgn hiiy hogi-mdi trudng loan cau, Tir dd, ngdnh ndng lugng da cd nhii'ng thay ddi cdn ban ca ve tu tudng vd cdc giai phdp khoa hgc ky thudl. nhdm thu hiit cdc nghien cuu phdt iricn cdc ngudn ndng lupTig nidi di ddi cac gidi phdp khai thdc sir dung ndng lugng tiet kicm va higu qud...
Hinh I. Du thuygn sir dung pin mat trdi Ddi \di nhung mang dien cue bd nhu mgng dien tren cdc hai dao cd lap hay tren cac nhd ndi, du thuyen.., ndng lugng can thiet dg ddp ung cho cdc phu tdi hien nay dang su dung van chu yeu Id tir may phat diOn chay 93
Ngo Diic Minh Tap chi KHOA HQC & C 6 N G N G H $ 118(04): 93- IOO nhign lieu hod thach (xang, ddu diesel) gay d
nhiem mdi trudng va tiem an nhieu nii ro.
Viec lua chgn ngudn phat thay thg dugc dinh hudng kha phd bien vao he pin Mat trdi (Photovoltaic - viet tat la PV). Trong trudng hap nay, ngudn phong dien khdng dugc lua chgn dp dung bdi nhirng trd ngai cua bd phdn turbine gid gay nen. Trong khi dd, cdc tam PV cd ban chdt tmh nhung ciing rat linh hoat hoan todn cd thg tao dang de Iam tang ve dep vd each dieu cho cdng trinh ndi rieng va loan canh ndi chung. Hinh 1 Id vi du mgt du thuyen cd sir dung PV [1].
Tuy nhien, cai gid phai tra cho ve dep va sir gin giir canh quan mdi trudng nay la ngudn PV cd hai yeu diem chinh [2], [3], [4];
- PV chi cd the phdt dien khi nhan dugc biic xa lit Mat trdi dii Idn.
- PV thupc dang ngudn sigu mem, dac tinh tdi chju anh hudng cua nhieu cac tac dgng ngoai sinh nhu bti'c xa Mat trdi (BXMT), nhiet dd, tdi...
Trong pham vi hep ciia de tai ndy cd hai yeu digm vira neu deu phai dugc khdc phuc khi dp dung vdi cdng trinh ndi trgn bien cd nhung dac diem rieng biet. Dd Id: ludn chju tdc dgng cua sdng bign lam thay ddi gdc nghieng ciia cdc tdm PV hay sir ddi hudng di chuyen ciia du thuyen cting tuong duong nhu thay ddi gdc tdi ciia tia BXMT, tham chi cd khodng thdi gian mat hoan toan BXMT.
Nhu vdy, mdt sd yeu td co ban vg PV can dupc phan tich dg cd dugc gidi phdp tdt nhdt cho su lua chon.
2. N Q I DUNG VA KET QUA Nguon phat dien quan trpng nhat trong he thong dien su dung nang lugng Mat trdi Id cac tam pin Mat trdi dugc che tao tir chat bdn ddn (silicon). Mgt each hieu don gian Id ndng lugng ciia pin Mat trdi dugc chuyen ddi hi buc xa ciia Mat trdi ma nd thu dugc [1, 2j.
Mgt bg ngudn dien pin Mat trdi dugc ghep vdi nhau thanh cdc module va ghep cdc module thdnh cdc mang pin Mat trdi. Mpt PV cd dugc dien dp danh djnh V va ddng dien danh dinh Isc nhu mong mudn hoan toan thuc hien dugc nhd thiet kg tir hai kigu ndi song song vd ndi ndi tiep cdc module. Cdc nghign ciru ve PV cd thg thuc hien tuong duang qua cac dac tinh da cd ctia module pin Mat trdi.
2.1. Nhung phan tich ca ban ve pin Mat trdi
Nhirng ddc tinh ca bdn cua PV dugc xdy dung xuat phdt tir cac phdn tich so do thay the
E ©
Rs -CD- 1.1.
Hinh 2. So do thay the ciia PV cua mpt module tren hinh 2.
va nhung mo ta toan hpc tir sa do:
Trong do:
- Ddng dien qua didt Ij:
94
Ngo Dire Minh Tap chl KHOA HOC & CONG NGHE 118(04)'93- 100
(2)
Is Id ddng quang dien bao hod [A/mm], q=^l,6.10''^C Id dien ti'ch ciia electron,
k=l,38.10"^'' [ J / ' K ] la hdng s6 Boltzmann's, n la he sd sd phu thudc vdo miic dp hoan thien cdng nghe che tao PV, T la nhiet do cua Idp tigp xiic p-n [°K], Rs la dien trd trong ciia PV [Q/m^] va thudng cd gid tri rat nhd.
- Ddng dien rd Isi,:
R,i, thu'dng cd gid tri rat tdn, vi vdy co the bd qua trong cdc tinh todn.
- Dong quang dien lpi
/.„=/..
'1000 tC,ir-T,^.^) (4) Isc Id ddng dien ngan mach [A], CT Id he sd nhiet dp ciia ddng quang dien [ A / ' K ] ,Tref la nhiet do tieu chudn, S Id tdng lugng bii'c xa thu dugc trgn tam PV d thdi diem xet [W/m"'].
Vi vay ddng dien phdt ra piia PV khi coi ddng dien rd cd gid trj rat nhd:
I = },„-!, e "*' - 1 (5)
Cdng sudt phat ra cua PV Id P = I.V.
Ndi cdch khdc, ddc tinh cdng sudt ciia PV dugc thg hien thdng qua bigu thuc 6:
K •'o J
til' dd, thu dugc ddc tinh Von-Ampe (V- A) cua PV khi cdp nguon cho tdi qua bieu thii'c 7
rfrJi._^^jl (7)
va bigu dien dudi dang do thi nhu hinh 3 Ut„(I)
0 Isc Hinh 3. Dac tinh V-A cua pin mat trdi
- Voc Id hieu dien the do dugc khi mach ngoai pin Mdt trdi bd mach Gia tri VQC dugc xac dinh tir bigu thiic:
(8)
- Isc Id dong dien ngdn mach do dugc trong pin Mat trdi khi V=0. Trong cac dieu kien chieu sdng thdng thudng, cd the coi 1,^ - I,,,.
- B Id diem van hdnh iing vdi ygu cau ctia phu tai (giao digm cua dudng dgc tinh ldi va dgc tinh V-A). Tren mdi dudng cong V-A, khi tai thay ddi thi diem ldm viec ciia he thong pin 95
Ngo Diic Minh Tgp chi KHOA HOC & CONG NGHE 118(04): 93-100 Mat trdi-tdi (PV-LOAD) se dich chuyen kbdi
digm B: sang trai khi tang tdi hodc sang phai khi gidm tdi.
Mat khac, tii' (5) cho thay V Id mdt ham theo bign ddng dien, tham sd nhiet do T vd cudng do BXMT.
• Anh hudng ciia nhiet dp T: nhiet do cdng tang thi l,,!, va V cang lang. Dieu nay thudng xay ra vdo Ihdi diem Mat trdi d thien dinh, ldm cho dudng cong V-l djch chuygn len tren, cd nghTa Id khi ddng tai chua thay ddi thi dien dp da thay ddi va cdng suat phat ra tang, (pham vi bdi bdo khdng ban them ve van de nay)
• Anh hudng cua BXMT:
Xet mdt PV dat ngau nhien tren mat dat nhu hinh 4.
A Phdp tuyen ciia ] mat phang ngang
Hinh 4. Md hinh hinh hgc tinh taan BXMT
Theo [2], gdc tdi cua BXMT ddi vdi mat phdng PV dugc tinh lien quan den cac gdc hinll hgc nhu phuong trinh (9):
COS0 = sin5.sin^.cos^
-sin^.cos^.siriiQ.cos/
+cos5.cosip.cosj9.coso) -FcosS.sin^.sin^.cosy.cosw -i-cos5.sinjS.siny.sin6j Trong dd:
5 = 23-45sin 3 6 0 - 365 j
(9)
(10)
vdi n la thii' tu ngay trong nam, to Id goc gid, (p la gdc vT dp...[2]
Tir (9), neu xet tuong ung cho mgt PV ddt tren du thuyen (tdu) cho thdy tai mdt thdi diem, COS© dgi dien cho lugng BXMT ciia PV nhan dugc phu thudc vao gdc nghieng p va gdc vT do tp dac trung cho dnh hudng ciia dp lac dpc thdn tdu, gdc phuang vi y dgc trung chuygn dgng xoay hudng cua tdu, gdc gid Mgt trdi 0) dac trung cho do tdc ngang cua thdn tdu.
Nhu vdy, khi tau dirng lai chd dudi tdc dpng ciia sdng bien ldm cdc gdc |3, q> va to thay ddi cd tinh chdt dao ddng, cdn khi tdu chuyen ddng gdc y phu thugc hudng tdu chay.
khi tdu quay vdng thi y cd the thay ddi dgn 360 , trong dd cd khoang thdi gian mdt hodn todn BXMT.
Tdm Iai, ddi vdi PV gan cd dinh trgn du thuyen thi BXMT ma PV nhgn dugc ludn bi thay ddi dan den dac tinh V-I thay ddi trugt tuong ddi theo true 1. Hien tugng nay dugc md phdng bang Matlab nhu hinh 5.
2.2. Nhan xet va de xuat giai phap
Ng6 Due Minh Tap chl KHOA HOC * CONG NGHE 118(04): 93- 100
lr-Da-a4M<il<Ai li-[MflHpV;v)
Hinh 5. Dac tinh V-A khi BXMT thay ddi do (P,(|),y,co...) thay ddi Nhu vay, diem van hdnh (B) ciia he PV- LOAD khdng thg cd dinh. Dg dam bdo dien dp tigu chudn thi digm ldm viec B phdi di chuygn ve phi'a gidm ddng dien khi BXMT nhgn dugc gidm va ngugc lai. NghTa Id he thdng cdn phdi cd thgm mdt bd dieu chinh dong dien theo su thay ddi ciia BXMT (theo dien dp) - Giai phdp thir nhdt.
Mat khac, khi mat hodn todn BXMT thi he cdn cd ngudn thay the. cd the Id tir mdt kho trir dign dc quy - Giai phdp thii' hai.
2.2.1. Giai phap thii' nhSt
Dg he pin Mat trdi ludn cdp ra mdi dien dp danh djnh khi tdi thay ddi nhdm dap ting ygu cdu ciia ciia phu tdi hodn toan cd the thuc hien dugc mpt cdch don gidn ngu ta sti dung bg bien ddi cd bg dieu chinh cd phan hdi dien dp. Gid thigt, quy djnh dien dp thay ddi trong pham vi(I6-l7,5)V, hinhd.
Mat khdc. neu ygu cau cao hon la dii BXMT Ihay ddi d gid tri ndo bg ngudn PV vin ddm bdo cap ra dugc cdng sudt Idn nhdt
0 S 10 16 » JS
Hinh 6. Phgm vi dich chuygn digm ldm viec B
cho phep tbi ta dp dung bp dieu chinh dong thdng qua khdi tu ddng chgn diem ldm viec cue dai (tgn lieng Anh Id Maximum power tracking for photovoltaic power system, vigt tdt Id MPPT) [5, 6 J]. Cau triic he thdng dugc md td tren hinh 7.
^71
Hinh 7. Cdu true he PV-MPPT-LOAD
Vai trd ctia khoi MPPT cd the duac lam ro tliong qua cdc kgt qua md phdng bang Matlab-Simutmk. Gia sii vdi ciing mdt kich bdn thay ddi cudng dp BXMT tuang ddng vdi hinh 5 cd sd lieu nhu (11):
[1*50 2*50 3*50 4*50 5*50 6*50 7*50 8*50]
[0 400 850 950 400 800 600 400 0] (1 1) Ket qud md phdng thu duoc;
Tap chi KHOA HOC &. CONG NGHE 118(04): 93-IOO - doi vdi he thdng cd MPPT cd ket qu
chi ra trgn hinh 8,
Hinh 8. Cdc dac tinh cua he PV khi cd MPPT, energyPV = 2,2 kWh - ddi vdi he khdng cd MPPT cd ket qua chi ra tren binh 9.
BXMT la 400W/m-, vdi ddng tai 2,5A cd djnh thi cdng suat PV bdng 0, khdng tdn tai digm lam viec B - tuong duong vdi hien tugng mat nguon. Trong khi do tren hinh 8; nhd co MPPT ma PV van cdp ra dugc Iugng cdng suat tdi thieu khoang 0,2 kW.
2.2.2. Giai phap thir hai
Khi khdng cd BXMT. PV se mat hoan loan dien dp. Gidi phap thong dung nhdt van Id thay thg bdng ngudn dc quy (Battery). Viec thiet ke mdt bd ngudn dc quy ket hgp vdi ngudn pin Mat trdi dap ii'ng cho mdt mang dien cue bd dugc phan tich tuong tu trong tdi lieu [8]. Ddng gdp tich cue ciia gidi phap thu hai trong trudng hop nay dugc thg hien d ch6 Id de xudt mdt cdu true hoan chinh cho mgng
Hinh 9. cac dac tinh ciia he PV khi khdng cd MPPT, Iref = 2.5A , energyPV = 1.49 kWh
So sdnh hai ket qua cho thdy: nang krgng cap ra ciia he thdng cd MPPT la 2,2 kWh. Cdn doi vdi he thdng khdng cd MPPT, khdo sdt vdi cdc gid trj ddng tai khdc nhau cho thdy vdi 1=2.5A thi he thdng cdp ra duoc nang lugng tdn nhdt chi dat 1,49 k Wh. hieu qua tdng them (47%). Han thg niia, tren hinh 9: d thdi diem
DC/DC 1=;;
Batteries ^
z=^ DC/AC 1 = ^ AC - Loads 230/110 V
Controller
, il
= > | DC/DC Y^
DC-Load!'
TT
12V-..40V
Hinh 10. Cdu tnic he thong dien PV tren du thuyen.
dien cue bd tren du thuyen nhu hinh 10.
Trong do:
- MPPT ldm nhiem vu khai thdc toi da cdng sudt ctia he PV ke ca khi BXMT tha>
ddi;
- Bg bign ddi DC/AC (hogc DC/AC) co nhiem vu chuygn ddi thdnh dien xoay chieu va DC/DC dieu chg cdc cap dien dp mgt chieu phii hgp vdi cac thiet bi diing dien khac nhau (tdi) trgn du thuyen;
Ngfl Buc Minh Tap chi KHOA HQC & CONG NGHE 118(04): 93- 100 - Batteries cd tdc dung nhu mdt kho trii
dien trung gian ket hgp vdi bd DC/AC cd dieu khign ddng vai trd ciia mdt thigt bj BESS (Battery Energy Storage System) Idm nhiem vu cdn bang ddng va ngudn du phdng, [8].
Md phdng he thdng bdng Matlab- Simulink thu dugc cdc kgt qua tren hinh 11.
vdhinh ]2a,b.
Hinh 11. Cac qud trinh nang lugng oiia he thdng
OU 046 048 0 5 052 054 OSS b)
Hinh 12. He thdng cd BESS ddng vai trd ngudn du phdng a) Bieu Ihi theo cdng suat b) Bieu thi theo ddng dien
Hinh 11. Chi ro cdc qua trinh nang luong trong he thdng: Uac. lac Id ddng vd dp phia tdi xoay chigu, Ppv. Ipv Id cdng suat va ddng phdt ra ciia PV, Pideal id cdng sudt 1;
tudng md PV cd the phat dugc.
- Hinh 12. Cho thdy cdng ndng ciia khdi BESS. Tgi thdi digm 0,5s . khi mdt BXMT dot nggt (do thuyen xoay hudng hay bi die khudt) lam PV khdng cd kha nang phdt dicn. tap tii'c BESS lac ddng ddng vai trd ngudn du phong vdi thdi gian gidn doan cue ngan, khoang 20ms (1 chii k\ tdn so 50Hz) (8] Tinh nang ndy dd ddm bdo cho he ngudn cd dp lin cay cao. dap irng yeu cdu ciia nhung hd phu lai quan trpng nhat nhu cdc thigt bi dien tir, cdc he dieu khien.. hay nhung du thuyen cao cdp.
3. KET LUAN
Kel qud nghien ciiu ciia bdi bdo dd de xudt dugc mdt md hinh sir dung he ngudn pin Mat trdi dp dung cbo du thuyen ddp iing nbirng ddi hdi khdt khe
- ve cac lieu chudn moi trudng cua mpt khu du hell - Ky quan the gidi,
- dam bdo cdc tigu chudn chat tuiyiig dien nang cung cap cho mpt hd tieu tliu loai cao cap.
Md hinh PV-MPPT-DC/DC,AC (BESS) cd tieu chi tict kiem dien ndng. nang cao hieu qua khai thdc nang luang tir ngudn pin Mdt trdi (\i du ldng them 47% trong trudng hap tren). dieu nay mang lai rai nhieu lai ich Thuc lc. trong lich sir nghien ciru \0 pin Miii trdi cac Nhd khoa hgc pbai mdi nhiiu iidni mdi cd dirge nhung cdng iighO lain tdng hicu
Ngo Diic Minh Tap chi KHOA HQC & CONG NGHE 118(04): 93- 100- xuat ciia mdt bd pin Mat trdi len vai phan
tram. Han nira, gidi quyet dugc vdn de tiet kiem nang lugng la ddng nghia vdi khdng phai phat trien them cdng sudt hay sd lugng ngudn phdt trong he thdng
TAI U E U THAM KHAO [1] Hinhl. Anh minh hoa.
[2] Hodng Duong Himg, Ndng lugng Mdt trdi - Ly thuyet va ung dung, Nha xuat bdn KH&KT, 2007.
[3] Ddng Dinh Thong, Lg Danh Lien, Co sd nang lupng mdi va lai tao, Nha xudt ban KH&KT. 2006.
[4] Thdn Ngpc Hoan. Ndng lugng dien Mat trdi va nhung phuang phdp nang cao chdt luang va hieu suat. Tap chi Khoa hgc Cong nghe Hang lidi. s6 18. 2009.
[5] .Ice-Air Jiang, Tsong-Liang Huang, Ying-Tuiig Hsiao, Chia-Hong Chen.
Maximum power tracking for
photovoltaic power system, Tamkang Journal of Science and Engineering, Vol.
8. No 2. pp. 147-153,2005
[6] T.Chaitanya, Ch.Saibabu, J.Surya Kupiari, Modeling and Simulation of PV Array and its Performance Enhancement Using MPPT (P&O) Technique, T.Chaitanya et al. International Journal of Computer Science & Communication Networks, Vol 1 ,Septeinber-Octobei^
2011.
[7] Roberto Faranda, Sonia Leva, Energy comparison of MPPT techniques for PV Systems, Wseas Transactions on power systems, ISSN: 1790-5060, Issue 6, Volume 3, June 2008. \
[8] Ngd Dii'c Minh, Nguyen cii'u ung dung he thdng tich trir ndng lupng diing dc quy trong mang dien cue bg thiiy dien nho, Ludn an tien sy Trudng Dgi hgc Bdch Khoa Ha Ndi, nam 2010.
SUMMARY
In this paper concerns with protecting and holding green - fresh - beautiful environment in exploiting and using renewable energy. When applying to Quang Ninh province - a nature wonder that uas ranked in 2012, author focuses on using photovoltaic system to supply electric power for floating projects on the sea, perhaps they are fixed floating building or moving boat.
Solar irradiance in this case, falls down photovoltaic system, differs from fixed photovoltaic system on land. Propose some technical solutions suitably to ensure demand, quality electric power and responding environment, aesthetic requirements at once. Build an isolated electric grid model that has structure as PV-MPPT-DC/DC, AC(BESS) and carries out optimal energy solution in photovoltaic system when irradiance intensity is always unstable Including loss SLiddenl\'. Research results are represented by simulating in Matlab/Simulink.
Keywords. Photovoltaic panel, PV-MPPT, PV-LOAD, PV-MPPT-DC/DC,AC(BESS).
Ngdy nhdn bdi- 13/3/2014. Ngdy phdn bien: 15/3/2014; Ngdy duyet ddng: 25/3/2014
Phdn hien khoa hoc: TS Nguyin Dire Tudng - Trudng DH Ky thugt Cdng nghiep - DH Thdi Nguyen
