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Dksmd

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Dksmd

  1. 1. LEVAN DOANHNGUYEN THE CONGNGUYEN TRUNG SONCAO VAN THANH.. ,,~ ,NHA XUAT BANKHOA HQC VAKY THUA.T
  2. 2. LE VAN DOANH, NGUY~N THE CONGNGUY~N TRUNG SON, CAO VAN THANHA A? KDIED KHIEN SOMAY DrEN•(Dung cho sinh vien cac truong ky thu¢t)NHA XUAT BAN KHOA HOC VA KY THU~THA NOI " 1999
  3. 3. Chla Irdch nhiiJm xw:ll /JdnBien ItJpeM IxiII :Ve bia :Ma ,,6:I·I!.!>. I·Lo;. TO nANG HAlN~uy~ f)iinl!:Trap Viill CamIhnm" IAIIKHKT-9fl41-91-99In 1000 euon kh6 16 x 24 em ~ COng ty in HAng khOng. Gi!iy phep xu!it bBn8641-91- 16/6/99. In xong va n(lp h1u ebi~u thang 7/1999
  4. 4. UJI NOI DAUTrong nhii:ng nltm gdn ddy di~u khiln may di/fn co bUGe phat trilnnhdy v9t. Do liz klt qua eua vi~c tang ctJng suat va cae linh ndng eua linhki~n di~n tit cong sUIlt uiI viifc pha! trilfn va Iwan thi~n cae co cau di~ukhitn so co l¢p trinh, eua cae b" vi xu ij, vi dieu khiCn. Truyen d¢ng di¢nthong minh dlja tr~n kJ thu¢,t dieu khien s6 cho phep tq.o nen h~ thongtruyen d¢ng di¢n c6ng nghi~p chae chtin, tin ca.y, hiiju ,mtit caD, dcii dieukhi{n rrjng, dam brio cae chile nl1ng bdo U~... vi du, IPM rIntelligent PowerModule) eua Mitsubishi Electric dcii cong surit til 10 Aj600 V den 1200A/3300 V, ASC 600 ella ABB, ALTNAR eua Telemecanique... ia eae bf) di"i!ukhiCn d{)ng co xoay chieu vai cae finh ndng eMit luong nhu M trnyen d¢ngmQt chieu.Nhung hq-n ehe eua hJ thurU luang tlf nhu sl/ troi tMng so, slj lamui¢e on dinh dai han, nhCtng kh6 khrm eua ui¢e tlwe hi~n die chile nangdfeu khien phl1c tqp dti thue day vi€,!e chuyen nhanh sang c6ng ngh¢ s6trong nhung nam 70. S,-! xuut hi~n ua hoan thi~n eua cae bl) vi xU if mqnhnhung nam 80 cho phep thlfe hien dieu khien vecto, tc!o n~n h¢ truy"~n d¢ngxoay ehieu co chat luqng caD. Kj thuq.t 86 eung eho phlip tgo nen cae thu{J.ttoan dieu khien phuc tqp ma kJ thu¢-t tuang tl! khong cho phep.Ngoai ra di~u khten 86 can eo Uu tht" quyet .dinh ve mq,t c6ng nghi!.CiLng mot ca eau dieu khien 80 co the d6ng var tro giao dii?n uai nguiJiUQ,n hanh, thlfe hien crie ehue nang ehq,y, dUng, doi ehieu, dlf bao, tu uan...Moi ehue nling phue tqp eua truy~n d¢ng dir;n deu co the giili quyet dU(Jcbeing cae co eau di"i!u khien s6. Di"i!u khien so con cho p/zep tiet ki€!m linhki¢n philn cl1ng, cho pltf!p lieu chunn !toa: vai cung mot b¢ vi xu If, mr)tedu true philn cung co the dung cho nwi ung dung, chi can thay doi nl)idung b(J nha. Cuoi eung nho tien b6 trang etlng ngM maeh to hap eho phepthlj:c hir;n cci"-e ehue nang phl1e tQ.P voi k[ch thude nho, d(J tin ct;ty caD, liImvii!c chric chrin.Tuy nhien di"i!u khien so may di~ cung ddt ra n/tCtng doi hOi kM,tkhe. Vi¢c thanh ltip cae lhu¢.t toan di,eu kllien ciln biet ro cae d4c t[nh euad6i tuqng dieu khien, ma hinh cua chung d cluJ" d(J lien tuc dlng nhu aeM" dO rai rgc. Dieu khien 096 to. dieu khien thai gian thue eua qua trinhphtle tQ.P, dien bien nhanh chOng, dai hoi hJ thu{).t li,!p trinh hi! thong £1mUe caD.
  5. 5. Dieu ldllen s6 nuiy di~n ta noi hQi t~ dia nhieu nganh hhoa hqc POcong ngM thuQc linh vljc kJ thuf!,t di¢lt, di~n tli cong suat, dleu khien tljdong, kJ thu.(jt vi XII 1:1... ddy La linh vue nit moi, chua dUQc gioi thi~u£lay dli uai dQc gid Vi¢t Nam. Cac tac gid mong mu6n tTtnh bay nhung coso t6i thu?i, thuQc linh vI./e di~u hhien s6 may di~n nhitm giup eho dQc girlbllae dau tllfp cq,n vai linh ul,Lc nay.Quyen sach "Dieu khien 86 may di~n" gom 9 chuang.Chuang 1. DQi rllang uc dieu khien 80 may dien, ITlnl! bay kllal quatnhilng udn di! co brin cua dicu khiln nuiy dien, so sanh kJ thuq.t dieu khUntllang tu va dieu khitn s6. So do kh6i tOng quat cua dieu khien s6 nuiydi¢n.Chuang 2. Co sd .ui I:y tin I!i¢u so la chuong co tinh cMit chudn bt,frrnh bay kh6,i quat co so bUn d6i Laplace rai rQ.e va oien d6i Fourier rairqc.ChuOl.g 3. Mo hinlt may di~n va of! bien d6i, trinh bay If thuyet maydicn t6ng quat, m6 kink lien tue !.iQ. ma hinh Toi Tq,C clla nuiy difn va OQbiell doi theo quan die"m dieu kllien.Chuang 4. He thong dieu kllien 86, tTlnh b4) phuong phrip phan tichhi! dieu khien s6, dij.c tfnil elk b¢ dieu khifn s6, phuong phap tinh cae yeut6 chiit luang cua Il{ di"l!u khUn 80.Chuang 5. Tong hqp he dicu khien so, trinh bay phuang phap Mng hqpM dii!u khlen sfi trong mien z, t6ng hap h~ dieu khie"n so tTOng kh6ng gianfIqnl? thrll.Cln/ong 6. Cau truc phlm Cling ut"l yeu cii-Ii phan miJm voi dillu, klli/Inso. trlnh bay yeu cau d6i uoi b¢ pi .ui If va c6c giao di(!n, d~ diem lq,ptrtnh phan mem eho dii.lu kllifn sri.Chuang 7. Dleu kllien so may di~n m¢t chieu, trinh bay cae van dephrin dell ua Mng hqp he dieu kkien so nw.y dtfn m¢t cllieu.Chuang 8. Dieu khien st; may di~n xoay chleu 0 che dQ x6.c lq.p, trinhbU.y phuong phap phan tich Va t6ng hap dieu kllien s6 may kh6ng dongbQ va dong bQ, dUf trr;mg phuong pllap dieu khien t/fa til thong rota laphuong pllap dang th6ng dung.Chuang 9. Dieu khicn 86 !J1a) (h¢1t ..lOay ciueu 0 cltedq qua d6, tTinhbay phuong pllap phdn ticll hi! dieu khien s6 may di¢n 0 chi d¢ chuyenmqeh va qua dr).QUYr"n .wich nay do cae can b(J nllom Dieu khien may di~n, B6 mon
  6. 6. Thiet bt di~n, Trl1iJng Dqi h9C Bach khaa viet. PGS. PTS. Le Van Doanhchit bien.C6 the coi quyt!"n Elach "Dieu khiPn ,;6 may dien" ta ph"lLn 66 sung ehogiao trinh "Dieu khlen tlf d¢ng trui~n d¢ng dien". Quyen stich nay dungeho sinh vien cae ngiLnh Thiet bt di¢n, TIj dOng haa Xl nghiep, Dieu khientlf d6ng, Ky thu¢,t do va tin hoe e6ng nghiep. Quyen such nay cung dl1qcdung lam tai lieu tham kluio cho cac k.Y sl1 di~n dang cong lac trong cacco qu.an nghien c/lu, san Iunt va eae lop sau dqi hQc.Vi trtnh dq va thoi gian eo hqn, sach hhOng tninh khoi sai s6t. Chu.ngt6i mong nhq.n duqc cdc gop y, nhq.n xet cua d6ng dao bq.n d()C. Mvi thl1til, gop y xin gUi r>~ B6 m6n Thiet bt di~n, Khoa Nang htqng, Truong Dqih9c Bach Khoa Hil. NOi, DT 8692511. Chung lOt xm cluin thanh cam an.Cac tac gia
  7. 7. ChlEllng IA A A K , , ,DAI CLJONG VE DIEU KHIEN SO MAY DII;:NCh11dng nay co dnh chat nh(lp 1ll,6n, trlnh bay cau true cua h~ th6ng diflukhien truyen d(mg di~n t11dng tl,i va truyen dqng di~n dieu khien bang kythu*,t s6, so sAnh uu khuyet diem cua tung M th6ng, phan tich s11 can thi~tphaj ph6i hQp ca hai M th6ng diflu khi@,n bJdng tl,i va dieu khien s6 trongtruylm d¢ng di~n, phan dch cac van de din s6 trong dreu khien truy1n d¢ngdi~. PhAn dch cac yim cau d6i vai cac kh6i trang dieu khien s6 may di~n.1.1 CAU TRUC HJl; TH6NG TRUYEN DONG DIJl;N1.1.1 So db kh6i t6ng quat ella h~ th6ng truyen dl)ng dit1inTren hinh 1.1 lit sCI do kh6i t6ng quat cua M ,~h6ng truyen dqng di$n gomnhreu kh6i chis. thanh hai m~ch chfnh:- Mqeh d(ing life gom bi) bien deli vii d¢ng Cd truyfm dqng. B9 bien doidong vai tro bitrn dOi di~n ap nguem cung cap ve di~n ap, dong di~n, tan sophu hQp voi yeu cau cua cac d(mg cd truYfm de)ng,B¢ bien doi co the la be) bien doi may di~n: may phat di$n m(;it chieu,xoay chieui b9 bifn d5i di~n tit: khuech d~ t~, di~n khang baa bOa; bi? biend6i di~n tit cong suilt, BI) bien deli di~n tit cong suat th1c eMit lit cac b¢ chuyen~p-Oieu !chlin Oi€u kbienvi tri: ~V- dong rJi~nfoe t!.aOi§u I.-hienf=~bg biin rJoit=80 diin} rli{ny If!naa."dt;~; .fj~crimbiin ~:~,dOng ,Ji~n h:ecamn lacJ9vi fr/~00 loc dp va vi lriHlnh 1.1 Sd d6 kh& t6ng quM eua M thOng truy@n dQng diil:n.7
  8. 8. ml;lch di~n ttl: lam vi(lc i1 che d~ chuy~n nw-ch tl,l nhi~n do sl,l thay doi cuc~l.nh cua di~n ap nguon ho~c chuyen rn,!ch cuang buc. Do sl,l horm thien cuakg thu~t di$n tu: conp; suat vai sl.! ra dai clla tiristo (1960), tiristo khoa bangcl,lc dieu khien GTO (Gate Turn - Ofr Thyristor 1970;, tranzito c6ng suat kgthu:,H MOS (Metal - Oxide - Semiconductor 1980), tranzito luang c1c c6ngcach di~n IGBT (Insulated Gate Bipolar Transitor 1990) voi cac uu diemchuy€fn m~ch nhanh, tlnh nang dong lip cao, chac chan, hi~u BUat cao, d¢ tinc{l.y cao nen ngay nay cac b¢ bien doi dien tu: cong suat hoan toan chiem uutheDOng cd truyen dong co cac loai dong cd IllOt chfeu, uong cd kh6ng dongb¢, d¢ng cd d6ng bo va cac 10<:li dQng Cd d~c bi~t khac. Cac d9ng cd nay dlf;;Ccung dip M.ng dien tip u, dong di~n i va ~o nen momen cunp; cnp eho too CdkhOng dfl c;ttp a day.Mqch dieu khien bao gam eac carn bien do Itfllnp; dimg dg danh gia cacthong s6 tn;mg thai cua lu~h dong h.1c va cac b~l di"~u khien tac dQng len cacth6ng sO cua bO bien d6i nham duy tri cac dnh nang cua h~ thong truyflnd9ng vI! toc do, dong di~n, mamen cung nhu cac ml,lc dich Illd may, ham, d6ichieu quay va cac chuc nang bao ve khacCae cam bien do luang tronp; hi> thong truyfm dong di~n thuong bao gam:- Cam bien dong diE)!n, thl1dng Ie. may bien dong danh gia tlnh trflng ul.angtai eua dOng Cd.- Cam bien toc do thlJdng dung may phat t6e, bo chuyen m<;lch quangdUng b/il thong tranzito quang va dia rna hoa.- Cam bien vj trl. dung dIa rna hoa va bl> chuyen lll.<:lch quang.Cae bo dieu khien co th~ phftn thanh hai loai:- BQ dH~u khien gan xac dinh thu tl,l va thdi diem phat xung rnoi va khoacac Hnh ki~n di~n tu cong Buat theo eac chien lude dfeu khien bl? bien doinham cung dip cho dong cd nguon di~n ap va tan so theo dbi hoi eua truyfmdQng.- BO diEm khien thui[Lt toilll nhatn giai quyel nhiing van de rieng cuatruYEm d¢ng nhu dieu khien toc df,l vA. vi trio han ch€ dong dipn, elic yeu caurna lllay ham va d6i chien. Th6ng thuang tin hieu ra rua kh6i dieu khien nay130 m6men.
  9. 9. 1.1.2 Dieu khh!n tllang tl,l va di~u khi6n 56So d6 khrii hinh 1.1 If!. so db M th6ng di~u khi~n truy~n dQng di~n t1.1dngtt1 quen bi€t. Trang ;;;d do nay cac thong so tr~ng thai cua cac khoi la cac d~iluqng lien t!c. Tin hi(!u tit cac b(.l cam bign va cac b(J di"eu chinh 18. cae daiIUQng li~n tuc nhAm duy trl di.ic tinr. cO cua dOng co thea dbi hoi eua ph! tai.Tren hinh 1.2 Ia Sd do di~u khien hOn hqp tuong tu va so dung dieu khi~ntruylm dqng di~n m(>t chiEm Sd do gam 2 philn:- Phan tUdng W haa gom cae eam bien da Iuilng dong di(!n va t.oe d(l, bodieu ehinh dong dien, b(.l bi~n d6i a dAy la b(J bam dieu bien d(.l r(.lng xung1 - - - - - - - - - - 1IB9v,xir1y 1,N£. Bo hl6u chinn U00 Icc d~Ph.i"lll<lnllto,rDBDRX dieu bien dO rOng )(ung. u di~ ap dieu khien bO bien deliv~ tfn hi~u d~t dong di~n " sai I~ch dong di~n, v sai lech lac doHinh 1.2. So dO chllc na.ng dl~u khi@:n hOn hop Wong III va s6Phan diEm khie:n so han g-om b9 vi xit ly Jam nhi~m V1,l dieu ehinh toe d(lva eae ehur nnn!! an tmi.n. dong b¢ hoa. Sl,t khae nhau cd han eua phan dieukhien s6 ;;;n ,"::1 dieu khien tuong tl,t la a ch6 vi(!e danh gia thong s6 trl.lngthai eua he thOng va dua tin hi~u dieu khi~n tien hanh thea tong bUde thaif;ian g9i lfl tin hieu rili r~c, tin hi~u luqng tit hOa hO!.ie tin hi(!u so, Lue do amoi thai diem rai rl.le co mot to hqp bit lUang t.in tue vi> h? t.hling. ell: thongt.in s6 hoc chi eo hai llllk 0 vi"t 1 va thong s6 trl.lng thai ella h(! th6ng truyend(lng dUQe danh gia bang m(lt day bit.B(l vi xlr If rling haat d(.lng t.hea nguyen If Iuong tu ho:l thai gian. Thl1tl! cae lenh dUQc thl,te hi~n thea tOng buac thai gian. Vi cae h(J vi xu If cokha nAng thl,te hi~n dong t.hai cae thao tae voi so IUQng ral Ion nen thai gianxtt If nl(.lt l~nh .may rat ngiin. VI d1 bO vi xtt Iy 8 bit co kha nang bieu diEln2k = 256 trl.lng thai, voi b(l vi xU: ly Hi bit la :l[(! = 65535 trang thai.De ph6i hQp giua ph:in so va philn tuong hr phii eei ho d6i t.udng tl! - s69
  10. 10. va b(l d6i so - Wdng tI,r. Trong cac ml,lc tiep thea se trinh bay chi tiet hOl.ltd<)ng cua b¢ vi xu ly va cac bQ d8i ti.fdng t~ - s6 va h(l doi s6 - tUdng tlJ.1.2 SO SANH DlEU KHIE:N s6 vA DlEU KHIE:N WONG TVVi¢c so sanh giua hai kg thul,l.t difuI khien tuong t« va diim khilln so ratur nh~ nhung cung riH thu vi. MOi lol,li dieu khien deu the hi¢n nhung uu vanhu9c diem, viec so sanh cho ta thay rO 51.! dm t.hiet phai chuyen sang kyt.hu~t diea khien s6.1.2.1 Cae h(l" chi cua dieu khU~n tllang tl,l 108 lIU diem cua dieukhU~n s6- Nhu9C diem quan trQng nhal cua kg thu~t. tl1dng tt! lien qUlin den s,!troi th6ng so do cac nguyen nhan co nguon goc khac nhau (do nhi¢t, h6a-ly,Cd hoc. )Cac hi~n tl1Qng nay lam thay d6i thOng so cua cae Hnh kien di~n tu, thaydoi di~n dung cua cac tl,l hoa, thay doi di~n tra cua cac chillt ap. Nhung hi~nb.1Qng nay dan den su thay dbi Ch~111 thOng s6 cua cae phan til, Hun xuilt hi~ndi~n ap l(ich hay di~n lip t.roi 0 dau ra cac b¢ khuech dl.li thu~t t.oan Vi(!c khlisl.! troi thong so doi hOi cac nha thiet ke 11ll.lch phai tim cae giai phap nhu sU:dv.ng cac 1111ilch bu lam phuc tl.lP nll.lch va bing gia thanh. Trang khi do caclinh ki(i.n so chi co hai muc cao va thilp (0 va 1) kh6ng ch~u anh huong cuas1 troi.M¢t nhl1t;jc diem kh:ic cua kg thu(tt tUdng tu la nhl.lY VOl nhi~u. Nhi~u coth~ phit. sinh do ban than linh ki~n (nhii2!u ve nhi~t) ho~c nhieu kg sinh blmngoiH do anh hUdng cua moi truong. LOlili nhieu nay d~c bi¢t quan tr9ng vI.t.rong vi{c dil;.u khi{n truyen d(>ng di~n cac bO bien d6i la ngubn nhitu ga.y:mh huang dang ke dEn tudi di~n.Cae cao truc so co t.he dl1Qc baa v~ chong nhiliu bang cae ky thu<)t lipdl,lng cho kg thu~t tuong t.1,l nhu man chan, b9C kim., ngoai ra ng"Ubi t.a thubngdung ky thu~t 19C so cho phep 10l.1i bo d.c diem bat thubng ma kMng hliln ch~dili thong cua llll.lchVi~l truyen dan t.in hi~u wong t1,1 cling !¢p khci khan do sl) suy giam tinhi~u, trong khi do truyen dan ti.n hi¢u so a ph~tn vi hqp ly khbng ch!u anhhuong cua 51) suy giam..Cac linh ki~n kg thu~t tudng t1,1 Cling co tinh chat khac nhliu ve th6ng)0
  11. 11. ;;6 khi dl1Qc Sfill xuat hang lo~t. Nguai ta cd the lo~i tru dUQc 81,1" sai khac vethong s6 bang phl1dng phap xac suat cling nhl1 chu y trong khi thiet ke chet~o, tuy nhien hiEm tUQng nay lam cho cac linh ki~n kg thu$.t tuong t1,1 kelUon d~nh va la nguon goc clla nhi~u.Vi~c th1,1c hi~n Dl.9t so chuc nang nhll nho hoac tr~ Mng ky thu,flt wongtlj gi.p nhieu trd ng~i, tuy v~y h).i cd th~ thl)c hi~n nH dOn gian bang ky thu(i.tso.Cuoi cling can luu y rang do dnh phllc tl:p cua vi.~c thl1c hi~n cac bl) di~ukhien kinh dien rat it chuc nang tl10ng tl) cd the dl1Qc th~c hi~n bang m~cht6 hQp va can den nhieu Hnh ki~n roi, vi~c thl,ic hi~n mach va hi~u chinhchung ton nhieu thai gian va cong su-c, d.n co nhieu tiep di~tn lalll giam d¢tin c~y cua cac nwch wong tl1. Vai lllU-C dO phu-c t~p ma m~ch tl10ng t1,1 trdnen bat hdp Iy thi. doi voi nwch so van de trd nen kha ddn gian.1.2.2 Uu dU~m cua thiet bi tllang til va nhllQc diem cua thil1t bi soN goai cae nhuQe diem da phan deh d ml,lc trlm, ky thu!t dilm khien tlldngt1,1 cung co nhung uu diptn ntH h~t ma khi chuy~n sang kg thu(i.t 96 ta phaihiu y giai quyet. Hai uu diem quan trQng clm ky thU:;tt Wong tlj do IS. tacdQng nhanh va lien tlC, trong khi do ky thu(i.t s6 we dOng ch~tn hon va xl1Iy cac d~i luQng Iii roi r~c. Cac mc diem nay d~t ra nhreu van de doi voi vi~cthiet ke h~ thong truyen d¢ng dit?n.The dQn.g nhanh: Cac hi~n tuQng di~n to trong may di~n va bi? bien d6ithuang di~n bien rat nhanh va cO th~ pha huy toan hI? he th6ng n~u x{ty ras1,1 co. Cac sd db wong h! tac dong gan nhu Wc thai trong khi do cac cd Callso mc dl?ng Co thai gian.V1l m:?t dfeu khH~n"96 van de thai gian tic d{lng d:Jt ra theo cac gdc dokhac nhau ti:Jy theo bai toan Cl the clla M thong truyen dOng btl bien d6i-d¢ng cO dit"m.- BQ bien dOi cham, vi du b¢ chinh luu tiristo lam vit?c VOl hroi 50 Hz,trong trllang hQp nay dieu khien so co the coi nhl1 TIlt ly tl1ong, co the thvehi~n cac chuc na.ng M.o v~ va. vi~c dil!u chinh dl1Qc thl,ie hi~n biing bQ vi xuly co tinh nang thong thl1dng.- B(j bien deli tae d¢ng nhanh, vi dl,l b¢ bam lam vi¢c a tan ::;6 hang chlckHz, trong trl1ang hQP nay ngay cit. bi) vi x-l1 1y tac u¢ng rat nhanh ding dinphii Il1u y d~c bi~t va phai d1,1 dnh cae chien 1uQc dieu kh;en d(a tren cac11
  12. 12. glai phan (e phan cung ho~c chuang trinh ph!n memV~ ml)t phAn cU"ng ta co the dl! kipn (ftc (au true khae nhau:" C;iu true IHi (rong do cae chuc nang doi h6i tae dim~ nhllnh vi dl;l nwehyong dong di~n dude thlie hi".n hhng cae Hnh kien tuong tit, con cae khai khacdung kg thm):t so,(:.( true hl),lh t.Dnn dlfa trfon ky thu~t gO co th€ d1,1a lren cae glai phapr.,lU tr(if kh:it nOll! ~r11 dung n1¢t hoae nhih: b¢ vi xU lj !fun "j~c song songhu;w 3rt d~tng cae phan tlt ben ngoai nhu b6 nho ngoai, bb d~m., m~ch logichlp trinh . Ngoai ra (0 the su dl.,lng bi? vi xl! If th6ng dl;lng hoac chuy{m dungnhtl b(:l xU: ly tin hi$u, b6 vi dieu khien th1,1e hi~n c~c chue nang dic bi¢LV{. m~t p11i.W 111(.m dl,fa tren cfic quan ni{lll tin hqc ho~c quan niqm Vpdieu khi6n tl,l d"ng,Ve m:.).t tin hQc chuClng tdnh phan mell.l can co linh ch::lt ciiu trlie, sud~ng ng6n ngiJ g~n vai ngon ngfJ may (assembly) hol}.c ngtm n~{ cap CaDnhung cflOg co nhung dQ.c dnh ctta hQP ngil" nhu ngi>n ngir C. Trong m9itrdang hqp nhling kh6 khan rifmg ("ua vi¢c l(tp tdnh thdi gian thlC 1a t$phung vaa van de an toan va tac dQng nhanh.Ve m~t di~u khien dut Tn cae gitti phap rifmg, vi~ mo Mnh hoa M lh6ngreti r~c dl,fa tren bi~n doi 1., bien tl~ng tMi nhUng cac phudng phap nay chidon gUm trong t:ruong hqp h$ th6ng tuyen Hnh W)t bien !OlQt bi€n VEto, ln9tbien rll}, tat ca cae bien co the do duqc. Trang trubng hqp may di(n Cl;I theIII nlliy di~n dong bo, kh6ng dbng b¢ hi phi tuyen va nhieu bien, mQt s6 bienquan tlqng nhU: mornen, ttl thOng rolo C1ia may dien khang dong bi), dongdi~n trong dAy quan eln cfw. m:iy dit;>n dong bb khong do duqc Cuoi cirng rnt)t86 thong s6 chl yeu cua may nhtt di~n lrd rota elm dong eC1 khong dong hokhbng pMi Iii. hang so. Vi nhilng dl).c dif.m tri>n mf) hinh ViI c~lu true ella mlilchoieu khien chn rllt nhieu van de ca.n phai giai quyet luy da co nhiim ..:6ngtrinh oe. e~p Leti "an de nay.Tue drlng liln lUi:D~c die01 tac dqng lien tl,lc eho phep cae Hnh ki~n hwng tv su d~ng hu:uich cho vi~c kh6ng ehe eae bien (dong di~n, dien lip) CO:ill bien thi8n rat nhanhva co the gay nguy hiem ve rhUdng di~n nay cac linh kien sO 111m vi(le Valcac dai 111~mg r(ji r~c va the hi(ln nhlJc!c diem trong linh vUe thn s6 bien thi~nnhanh12
  13. 13. - M9t so phep toan lien t~c thuang du(}e S11 dung trong ky thu~t dfeukhien, thong d~ng nhat la phep deh phim. BQ hi~u ehinh PI (deh philn ty l~)dieu ehinh dong di~n bien thien nhanh t~o nen ache dQ xtie I~p gia trj dongdi~n trung binh bang gia trj dong di~n dl)t, trong khi do b(:t tieh phan s6 chieho gia t.rj gan dung ~llu gia trj trung blnh nay.- lJa so d~i lu(}ng gl.lP trong thvc te ia cac d~i lu(}ng HEm tue. Dieu khi€nt.huan .,0 doi hoi sv d~ng cae bi) doi tttdng t1,t - s6 sau bo cam bien. Vi$c nayd:t ra van de d(:t chinh xae va s6 hit do dUQ"e d6i voi dnh toan trung gian vadoi voi cae bien ra tac d(:tng len cac eo cau eong Buat.- Ve m~t rai r:.e hoa, vi d~ eac dUll bien toe dq neu ta chQn hq dim bientac dqng theo tan so, vi~c do se t.ien hanh trl,tc tiep duol d.;mg s6 nhung d:tdt/<;lC dQ ehinh xac cao se doi hai nhieu thai gian va ehu k5 lay m:1u phAi Ion,dieu nay la bat l<;li cho vi~c on djnh eua illach vong dieu chinh, d~e bi~t. Q fanso thap. vi the nguai ta tro I~i sit d~ng may phat toe va hi) bien d6i tuongtv so co dai thong tot ho~c thay doi d¢ ehinh xac (s6 bit) tuy theo truang hQPsil dung va dili toc do (t6c dq eao, toc dq thap, dieu chinh toe d¢, dieu chinhvj t.ri ..J. Dieu nay d(1t ra van de ve lay mliu b:h buqc phlti co thai gian thvchien cac phep tinh dm thiet.- Van de IUQ"ng tv hoa cling rat nh1.lY cam khi Jilill vi~c voi momen nhatlong vi~c oieu chinh m{lch vong dong di~n. Dj{~u chinh sO dnh toan mrle d~tdong di~n, a mue thap ehuan dong di~n ling voi so bit nha, do do kho xacdjnh. Nhi?u gay 1a do viec Iu(;mg til hoa se Ion vA. d~ tao nen cae sl,l co, VI d~t:.o nen dao dong.DIm gitin I(i thiel k€ eua Ji"eu khien lurTnK WTrong m~c t.ren t.a thay rang dieu khh~n tuong tv t.ro nen n~ng ne doivoi cac d;~u khien phrlc tap, tuy nhi~n amlic dlj ca c!lu hQP Iy thi diEm khientl1dng t.1,1 I~i nIt dan gian ve phudng dien cau true.Thl,1c v$.y vi ::;v hQ"p Iy ella thiet hj ho;,e do cae t.hu nghi$m tieu chuan hoa(dap ling dieu hoa, dap ling xung ddn vD nguai ta thl1ang co thai quen timkiem cac fila hinh toan lien t~c hang cae phuong trinh vi phan, ham truyend~t. va xac djnh kha d~ dang M so khu€eh d~i va hang so thai gian eua hi)die.u ehtnh. Cac mo hinh nay Iii. gan dung nhung cae ky su biet TO chung dUQcslr d~ng cho t.fnh toan sa h(:l cae b6 hieu ehtnh con cae thong so cua no co theduqc tiep t~c hieu ehinh b1l.ng thVc nghi~m t~i eho lAp dat13
  14. 14. SIj tim kiem cau truc dlja tr€m viec Stl d1,lng cac m~ch yang long ghep van~-~~~-~-~-~~~-~-­di! giai quyet hem. Trong cac diU truc nay dau ra clla bl? di"€m chlnh ung voim¢t Yang, vi d1,l m~ch yang t6c d6 tTd thanh dai 111c;mg d~t cho b(:l diflu chlnhcua m~ch yang b€m trong, vi d1,l m~ch yang dang dien, Cac bien nay lit cacd~i h.1dng vat Iy, lien t1,lC nhtt dong di~n, t6c dQ dttQc do bang cac cam bienttwng tl,l cung clp cac d~i 111Qng lien tI,lC Ia cac di$n lip s1.1 d1,lng m(lt eachtrl,lc tiep Tom l~i vi~c thi/~l ke m~ch dieu khien t.llcrng t.l,l va lien t.1,lc Clm Mthong dan den cau truc diim khi~n ddn gianTrong khi do dieu khien so thl10ng d1.1Qc coi Iil. di~u khien phuc tap. Cacbien dieu khien khd truy nMp, trit trllong hgp chllcrng trinh phAn ml:!m da.dV kien. Neu ta Stl dung- b6 vi x1.1 If de thvc hi¢n nhieu chue nang can phaithVc hi~n tam nhin tong the. Dieu khien so cd the Hnh h9i Hnh thAn clladieu khien h1dng tv doi voi cac mach vong ben trong: lam gan dung lien tiep,chia cat bai toan Ian thanh cac bai tOlin nho nhllng vi~c thvc hi~n bltng 96khang Hnh ho~t nhu dieu khiPn tttcrng- t.11.- Chllcrng trlnh phan m"em phai x1.1 Iy tren mot khoi toan bO cac van dema dieu khien tlldng tu giiii quyet bang cac l11Mun rieng re,- Viec thay d6i cae h~ so cua cac bc) dfeu chinh so t€ nhi hcrn nhieu sovoi vi~c hieu chinh be) dieu chinh tucrng b,1. Khi thu nghi~m m~ch tucrng tl,1ta co the dieu chinh tit tit cac thOng so Ine)t cach an toan, trong khi do voiky thu~t 96 l11"t IOi ve so cd the gay nen M.u qua nghiem tr(;mg.- Cuoi cung vi$c L1y mau rat d~ gay mat 6n djnh va kh6ng phiii baa gidcung co th{i" gW dU<;jc thOng s6 cua chu ky lay mau do anh huang cUa thaigian tinh toanoDo v~y eac 1116 hinh Sil d1,lng thl10ng 13. 1116 hinh lien tl,lc, dan den cacthuit toan dieu khien lien tl,le sau do lam gan dung bang eac thul}t toan rain:te.Chien luQc nay co nhung h~n che (xual hiiiin dao dong ho~c mat 5n djnhma cac mo hlnh lien t1,lC khang the dl,1 tinh het), vi the vi{Jc m6 hinh hoa h~thong thea quan diem dieu khien so dUQc phit trien rat m~nh. Ta se thAy 16trong cac ehucrng tiep thea cae phudng phap bieu dien toan hQc 1a cOng Cl,lquy gia doi vai vi$c tong hQp quy 1u~t dieu khien khi ta bien ddi cae m6 hlnht.oim hQc thanh cac ,,(1 do chtk mmg,
  15. 15. 1.2.3 Cae LlU diem c6 tlnh chat quyt d!nh cu. dieu khin s6Ta thay rang trong cac lInh vl,lc quan tr9ng dieu khi~n tuong tl,l co Liudiem n6i bAt so vdi di~lU khien so: do Ia dnh tac dong nhanh, Mc dOng li{!ntl,lC, st dOn gian cua diu truc dieu khien. Nhung neu dieu khien may di~ndAn dAn chuy~n sang dieu khien hoAn toan s6 IA do cac d$.c dnh quyet dinhcua cac Hnh ki¢n 96. Cac Hnh ki¢n so cho phep thtc hi~n cac thao tac phlicll;tp duoi d:;mg rAt chIle chan. Do dnh cMt nay noi chung 80% linh ki~n com(l.t tren thi truong hii?n nay la cac Hnh ki(ln s6. Do v~y mOt trao lLiu chungtrong ky thu~t la chuyen ttl ky thu~t hldng tl,l sang ky thu~t s6 rnA dillu khillnmay di(!n khbng phai Is. truang hQ"p ngofJ.i I¢. ThlfC vi[l.y, ky thu~t s6 cho pheptAng ty s6 gilla dnh nA.ng va gia thAnh. Cac uu di~m cua ky thut),t s6 th{i hi(!ncJ hai mat:Dieu khi€n thijng minhCac chuang trinh phAn m"{illl cho phep t6i uu hOR di"eu khien va thay d5icac dnh nang mong muon, VI dl di~u khien rna men hoac t.u thong kh6ngdoL .. Co the thl,lc hi(ln dieu khien logic phuc t~p nhLing trong truang hQ"p naygia thanh thiet bi r:it dilt va ton nhieu thai gian thl1c hi¢n. Nha di"llu khienso ta co the tru tinh cac d.i tien, Cll the la:- Trong do luang va xu Iy tin hi¢u.- Trong vi¢c danh gia cae d~i 1t1Q"ng ben trong h¢ thong (tu thong, cacbien theo d9C trlc d va ngang tr1,lc q) ho~c cac bien ngoai khi ta muon lo~ibO ml)t so cam bien VI dl dun ·bien toc do.- Trong vi¢c xay dl,lng cac thui[tt toan rn~nh han cac b(l dieu khien PIDkinh dien vi d1,.l nhu dieu khien phi tuyen, ho hi(lu chinh tl,l thich nghi, Mth6ng co rno Mnh chua":n, che do tntQ"t va hi¢n nay Ie. dj"llu khien rna, dif!ukhien nOron.~ Trong vi¢c tu viln bao tri va phat hien sl,f co.- Trong vi~c tn;l giup tl,l dong hoa qua trinh (Ina- l1uiy, ham, tinh toanquy d~o chuan).Viec tang cae tinh Dang nay eo the lam giam gia thanh do vi¢c don gianhoa ve philn cung.Dan Kian hOa lhifl hi, t;eu chufin h6a va tich hflP h6aVi cae chuc nang dieu khien dl1Qc thVc hi¢n chu yeu bang philn mem, cho15
  16. 16. nlm voi cung mQt thi~t bi phan cung onl)t bt) vi xu ly va cac giao di~n) dut;lcsit dl,lDg cho mQi 11ng dlDg. Dreu nay dan den giaill cac chi tiet d1,l phbng, dodo lilln giaill gia thanh.MIJi.t khac dfeu khien may di~n IuOn nllm trong khung canh t1j d"ng hoatoan btl hi? th6ng, ngay nay dut;!c thlJc hi~n bimg may t:inh. Vcri cung m"t congngM (sCi va cilng cac b¢ vi xu ly) co the th1jc hi(!n muc phan cAp t! dQng hoakhac nhau, Hun de dang cac dch hQp va dong b¢ hoa llWi phan tu. Cae dnhchat nay khOng de dang nh~n dllQC vdi tll hQp bao ghm mQt may dnh trongtam, cae otolmit l~p trlnh va cac b¢ di~u chinh tt10ng t1,1-1.3 XU HUONG PHOI HOP mEU KillEN so vA D1EU KHutN TUONGTVDo cac d~c diem da neu a tren trong linh v1jc dieu khit?n truyen dQngdii;m xu huang hQp ly Iii. dieu khien s6 dUQc th1jC hi¢n trucJc het a dfeu khientoc dl) va vi tri ciing nht1 dieu khien so bl) bien dlli. Cae chllc nang dbi hOidiE!U khien tac d¢ng nhanh duQC th1jC hi(!n bang dieu khien tuong t!. Cacchuc nang a muc d(l cao, di~u khien th6ng minh nhung th1,lc hil;m ch~m hanse duQc th!c hi~n hllng kg thUt).t s6.~n hlfu-=C"-=ro=~"-t______-1L __~O::..c .llIft"=---_~.,_--1 A ()o hit/no til " ,..!....- N " ;J. eo cOm hien vQxlllyHlnh 1.3. Cau true dieu khien sO dOng cO di~n mot chillu.Ta tra I:;ti vi du sd do hlnh 1.2 Cau truc dieu khien so cua sel do hinh1.2 duQc cho tren hlnh 1.3.Trong sd do nay ta nh~n thay co sl) ket ht;!p giua dieu khien tuong t1,1 vadi"eu khien so.16Co s! phan chia cac diE!U khien dong di¢n, toc d(l Vll vi trl.Dua vao cae: tin hi$u lien quan den an tOlill.
  17. 17. - BQ dieu khien s6 dlla tin hi(>u dong Il(I hall.Ml}.ch vbng lUang til in m(lch dieu chlnh dong di~n va b(l bi~n d6i phAirot nhanh va 6n dinh d~ dong di~n phdn il:ng dQng ca tac d(mg giln nhtl lil:cthai . Chufln mil:c dong di~n dllQ"c tlnh toan bang bO dieu chinh 56 toc dQ. Lienh~ giua cac phhn di~u khien 86 vA. dieu khi~n tllong tv nha cac bQ d6i wangttJ- s6 A- D va b¢ d6i s6 - luong l~t O-A. BQ di?!u chlnh thuang 11 PID ,,6. Mohlnh loan hQe ella M th6ng va phllang phap phftn deh h~ tMng dieu khi~ntruyen dOng di(!n mQt chieu s~ dllQC dl! c~p trong "huang 5.1.4. PH61 flOP D1EU KHiEN TUONG TV vA DIEU KHIEN s6 TRONGD1EU KHlE~ DONG CO KH(JNG D()NG BO&0-,. baPh. "-";!--!--1MayblMap KungCuv chI pha CBp vi xV Ii580,8# sasanllHlnh 1.• 0i8u kh~n dOng cd hh6ng dl.ng bO r6to dAy quAn ph6i hdpd~ khiin hJdng IIJ vi dlkJ khiiin sO.11
  18. 18. De lam sang to tinh than ph6i h<;lp dil!u khien s6 va dieu khien tt1dng t1,lta xet so do dfeu khien d~ng co khong di"ing b~ rOta day qmin co hai nguoncap tren hlnh 1.4.Stato dut;lc cung cap tit lubi 50 Hz, dieu khi~n dU:9c thllc hi$n Mng vi~cdi~u chinh nguon cung clip cho rota qua b~ bien tan ba pha. Moi pha rotadU<;lc n6i voi hloi qua hai cau Graetz n6i song song ng119c.Tr{m Old do hint"! 1.4 ta nh~n thay:- Phan di(m khien tuong t1,i baa gom mliy phlit xung va logic chuy{{n m~chcua chung.Philn dil~m khien s6 tht!c hi$n m(:it s6 chuc nang dieu khien b(l bien tan:• Phat tin hi$u di"eu khien ba phaXac dinh thai diem chuyen llwch cua m(:it cau so voi cau kia bAt da.ut1 s"l,i deli dau cua dong di~n. Dieu nay dUQc xac dinh nha b<) lQc co tans6 cat dUQc kMng che.Tinh toan dieu ki$n dau cUa goc moi cau ngu<;lc (If2. = Jr - 11) de dAmbAa s1,l lien b,lc cua di$n lip trong phs co lien quan.1.5 VAN DE TAN s6 TRONG DIEU KHiEN s6 MAY DI~NDe thay ro cac van de d~t ra voi dieu khien so d~c bi$t neu so slinh voidieu khien tuang t1,l ta xet vi dl,l dau ti~n ve dieu khi~n trl,lC trong robot. Taco the dLla ra co thai gian th1,lc hi¢n cac dieu khien khac nhau tren bieu dothai gian d hlnh 1.5 gom 6 muc dieu khh~·n. Trang l$p trinh thai gian thvcde thvc hi$n nhiem Vl,l nay ta co the gia. thh~t rang mlii chuc nang dUQC th1,iChi$n bang mot chuong trlnh con rieng re nam trong DlUC Ull tien ngat rieng.Vi ly do an toan so cang Ian muc Ull tien cang cao. Ta co the dua ra gia tridien hinh cua chu ky lay mllu gan voi tUng nhi~m Vl,l. Nhu v~y co thEi phAnra cac nluc sau:Muc 1, chuan vi tri dUQc hien thj vm chu ky co 10ms;Muc 2, bt) dfeu chinh v1 tri, may tinh quy d~o voi ehu ky My mau 10ms;Mue 3, ma.y phAi dap ung voi toc d(:i trong khoAng vai mili giay. DAitMng Me d9 vao khoang vai trAm Hz, do do chu ky lAy ma.u co mili glAy.- Mue 4, momen phili dap ung trong khoang vai tr6m micn) gilly, cae m~ehvbng dong di~n phAi co dAi tMng vai. kHz, chu ky bly mau khOl:lng 100 J.1s;- Muc 5, bl) nghich luu cung ctlp eho d¢ng Cd cha:p hanh dung sO do tranzito,18
  19. 19. tan s6 chuyen m~ch thuangIon tu 5 den 20 kHz, chu kybam la 50 fiS.- Milc 6, m6i be;. bien doiphAi kh6ng ch€ d1l9C cac hi(mtt/9ng di~n xAy ra rat nhanh(an to~m, giarn sat 51! chuyennWch cua linh ki~n, do dokhoAng thai gian co microgiay ho~c nha hdn).Mot vi dl khac ve bieu dothai gian la bO bien d6j toc dOde;.ng cd dUQC cung cap bingbO bien doi chuyen m~ch tl!nhit"m bang cau tiristo a tanso 50 Hz. Ta c6 cac rnlilchvong dong dit"m va doi voj be;.ngh~ch 11lu co tan so rat thilp,Trim bieu do thai gian hinh1.6 tan s6 chuyen rn~ch eua,chu ky may f(nh qui ,juo - Jams-(hu kif b{j ,ji€u chihh vi fr; ~ /0 ms(nil ky bo (lie" eli/nk IDe tla., tmsChu,;: bOJjig~~lnhdon (lifn Jo SChI! ky hdm rhu kif ,,, hi !J;en rfai gidm $fjf 3,, "50]i , ~lpS ,~,"" Jri1~ 6lf6lr6l"- ----Hinh 1.5. Si~u d5 thdi gian di~u khi~n trueraMt b~ng bO nghieh Illu Iranzito., y" m -mchu ky bp (Mu chin/!d009 Jien3,]ms, clw ky enuye}" ,, milch bp Nlnda; 4 s,~3,lmS,~bi? bien doi 113. viii tram Hz,thai gian dap ung so voi bieudO hinh 1 5 chi ling voj 3 milc Hinh 1.11. Siau do thdi gian bQ bign dOi ehuyiinm~ch tV nhi~n bA.ng bO chinh Illu tiristomac 3: dieu chinh toe do;mac 4: di"E!u chinh dong di¢n;muc 5: philt xung di"eu khi~n hi? bi{fn doL1.6 BAI TOAN DAT RA DOl VOl DIEU KHIEN SO MAY DIeNDieu khien so nUly di¢n la dieu khien thai gian thljC clla d6i tL/9ng co rnahinh toan phuc t;:tp. N6i chung nhi$rn Vl dieu khien so nHiy di~n dUdC chiathanh cac blloe sau1.6.1 Xiy dvng mb hinh dieu khi~nXuat phat til nhiem Vl dieu khien truyen d¢ng diE;!n ch(;m sd do bo biendoi va d(mg Cd tnlyen d¢ng thich h9P, xay dl!ng sd do rn<),ch di?ng ll,lc va dieu19
  20. 20. khien. TO: mo hinh tong quat phan tich va chia thanh cac vbng diEm khien.Phan cap die vang dieu khien xac dinh vang dieu khien tudng t1,1 va vangdieu khien ::;0, ch9n chien IUge dieu khiEn.l.S.2 Xciy dl,lng mO hinh toan cho he trUYEm dQng di~nXay dl,lng mo hinh toan eho bl? bien d6i dQng cd truyen d(mg va mo hinhtoan cua cae cam bien do luong, cac co cau so sanh, chap hanh.1,S.3 Xac dinh thong so cua cac m~ch yang tuang tl,lCan ell vao cae dap ung Hnh va d(>ng va ket cau m~eh vang dieu khientuong tv, phan tieh va tong hop thOng 56 m~eh vang tuong t1,1 dua trEm co soham truyi;m va bien deli Laplace.1.S,4 Xac dinh thong 56 cua m~ch Yang di~u khien 56Nhi$lll Vl,l nay baa gom hai van dA quan trt;mg:- Phiin cling: ch9n bo vi xli ly cd bit may, toc do, dung hieing bo nha, s6giao dien VaG ra t.hich hl.1p eho nhi~m VI,l dieu khien.- Phan mem: MC dinh ehu ky lilY nul.u va lap trinh eho m~eh di"eu khienso. D1,1 t.inh d.c ch(ie nang bao v~, an toan, lien dQng v, cac ehllc nang malluiy, ham dong cel. De thVc hi$n cae ehue nang nay t.a se si1 dung eac m6hinh so d-lJa tn?n bien doi Laplacp roi rac (hien d6i z), ph,n tieh m~ch dieukhien tudng tl,l va so dua t.ren co sa grafeet, m~ng Petri. Chung ta se phantich chi tiet cac van de nay trong cae chuong sauDe lam vi du ta xet cau trlle t6ng quat ella h$ thong diCu khien hoantoan s6 dong dieu khif,n dong cel mot. chieu gom cae mach vong dieu chinhdang di~n va dieu ehinh t6c dQ. TrEn hinh 1-7a 1ft sa do chue nang, hinh 1-7hh sa uo bf.i t.ri phi"m eung va hinh 107c 1< bi~u do thai gian. May tlnh thuchien nhi~m vu bo dieu ehinh cling vdi cae C<l.Ill bien tac dQng len bQ bien doi]fl b6 ham dong di~n 1119t chieu cung cap di~n eha d9ng co Trong so do 16 trlphan cling hinh 1-7h ta nhan thay co su phan ehia nhi~m Vl giila 2 may vitinh:20May vi tinh chinh d,m nhipm·Dietl chinh vi t.riDieu chinh toe dQDieu chinh dong dien
  21. 21. ----- I Cdm-bieiJ~____--J--- -- ------ ·1 Cam hien d:EZJ-------------May I/nh chinh_Dieu chinn vi ki_Di€1/ eh/nh lo~ do_OI€U chinn dong dl~n_An foon· T/nh cae (tiling ddl vi fri· Giao hip· Ghi~ D{~IJ khien fruyen dJ Ilfli0) Sd di5 kh5; cllI/C nangh) Sd clJ ba fr/ plufn cIIng, _____________ Do vi Iri____________ Da 10 dpr- ______.._ Df} dang dien .,,- __ fin h;§u Jieu /chien &5 bIen £J, r--- -, B" d" I : I "~ ~2 O,eu chrnh vi Irr pp H--t----L+-T- pp ~ I I I:1-3 [),1!u chlnh toe do L_l1U~_ ~__~_4 5_~---:__ 7i_~~_ 3 ,4 ~ 674 Oieu chlnh dong dien i: ________ ~-----+-i ~5 Chu.in bl d,1!u chlnh dong olen : Tcv " I, fo------ ________-----j----".f6 Chuiin bl djeu chinh tOe do: Tcp-7 Ghl :T- ------------j,PP Tni ve chudng trinh chtllh J.o- __To, Chu ky lay miiu cua bQ dl1!u chinh dong----i!-- ----T, v Chu ky lay miiu be dleu chinh toe d6c) Bie.~ da Ihiii gionT,." Chu ky lay mau bo dieu ehlnh VI IrlHlnh 1_7. Cau true he th6ng dleu khien hoan toan 0.6.21
  22. 22. An toan, baa v~Danh gia momen can nhall1 nl1,le dich btl dl).e dnhTinh tOfin cae gia tri d!).t vj trlGiao tiep voi ngttbi dieu khienGhi cae sl,f ki~nDieu khien vi~e truyen du Ii~uMay tinh thu: hai dAm nhiem viee xu If du Ii~u vi trl.Ta nhan t.hay cae thai diem lay UlaU ling vai cae m~eh yang khac nhaukh6ng dttqc dong b¢ hoa. Ta co t.he dnh d@"n dieu nay bA.ng each dua va~ thOigian t~ trong cae m6 hlnh eua ham tTuyen. De xilc dinh b¢ dieu ehinh taphai nghien cuu tirng yang dieu chinh bat dau tu yang trong nhat rai Ian luqtxet. tirng yang ngoai.Theo quan diem If thuyet diflU khien tl,f d(lng bieu do thai gian toan MthOng dUQ"e cho tren SCI do hlnh 1-8.00 dqctc T~ui giO!l linn (oancan !/Jlet cho a;ell kniln t~, Thill rian tlhh loan clllltin hiclio r:hll ky lIip th~oI I I: I_Df Ire~9ay ~11 !uTi bp bi~~(O;= 1fI I II DOfrifudngdtlongfOng .. r; I t NT-r; I••------~~~~~~~~~~~--~,----------.il·.----~--~-----.I I II Cnll KY T I T II~·__________-C~~~~__________·,i··----------~------------·I II NT(U-d;yN=2) II-·----------------~~~~----------~·,Hlnh 1-8. Bieu do thai gian eua hI;! di.. khign hoan toan s6.D6i vai h~ th6ng dieu khi€!n ngttoi ta t.hltong phan thanh 2 tTl,lC:- Truc d¢ng Il,fC gom nguan dien, b(J bien d6i, phu t..1i di$n CCI gdln d(Jng
  23. 23. --NgUOn ifn , ral jBp hien 1I0i finn. j~True dOllg Jut:, BP t:!i~U khie~ ,;0,.,,~ 1.,~ ~!:~.~Macy lin/! ~, ,i:% ~~~ ~ Bp (!feu Hie-n L:eire-dO hot? t!$1Jj!,IGia(l flip,,, Gia frj cf;lHlnll ,.8 C.!u tr(,!c chung h~ thOng ky thu$.t dUQc dibJ khien bang may tfnh.Ir·············· ---------,IiB9 hien rJ6i linhIN9uan ifn t~MoyPdifnr ~Co eau lac orinJ8# aim bien (foe rip, ..!Ir( tlifn ip,tlring 1I1f1l)11111 ( )89 tfi€u khiin,mI J Jc )May hi7h lillie hltffJ eric fl1IJ¢1/rXmtI G-om ,01 chung !Hlntl 1_1D M6i rll~n M gilia tr!,le dong Il,lc va do Itldng dieu khien.23
  24. 24. l:d di~,n va e~lc h~ thong truyen d¢ng.1r!,ic do luong dieu khip·n bao gam:B() dipu khie·n mai, xU: If c:-ic ehue nang logic dieu khien ehuyen m~eheua cae bo bien doi. Do IA eae ehde nang lap I~i, ed tan so eao, dnhden an toan eho dc Iinh ki08n di~n ttt cong suat. Van de nay co the xuIf bang cite llH.lCh doc 11~p hm)c dua vao trong clie chllc nang eua bo vixV If toe d9 ca~ .• May tinh lam nhiem vu dieu ehinh (ll1~eh vong dong di~n, toe do, vitrl. Hnh tonn quy dQ.o, urinh gia cae dai IUdng khOng do dUdC, bil anhhuang nhipu, bil phi toy~nJ. Vi! llltt phan et1ng c(; thp· su dlng mothoac nhfeu uQ vi xV l.v hmle c,ie linh kipn chuyen dung khae.• B) dieu khien ehe do hO:.lt d¢ng. Do la cae Go gi}im sat xfie dinh eaeehe do h01.1t dong: ehay, dirng, 1110 nItiy, rhM hi~n Sl( co.Trong khoi do lui1ng dieu khi~;n tif,u chuan hie d¢ng nhanh dong vai troquan tn:mg. MOt so chac llang nam d tanh gidi cae khoL Neu ta muon thvchien lll(lCh vang dong dipn t:ic dong nH nhanh ta eoi nhifl1l VI nuy do b6 dieukhiiin gan IhVe hipn Hlnh 1-0 hl. diu t.rue chung eua hp thong ky thu3.t duqeelif-,lI khipn hilllg m;:iy dnh, can hinh 1-10 hl. moi IiEm hf gitta trl,le d¢ng lLieva t.rlc do itrong diiu khipn.Ta nh~n thay h~ thong dipu khi~n ;;0 nuiy djpn Ia kH c11n phue t.1!-P trongdo may tinh thalll gia vfw qua trinh do Iltang, dfeu khi6n, xV Ii tin hi~u nhil.lllt.ae d¢ng len he thong dong il,il: gaUl ll11iy di~n v;t b9 bien doL 0 dfly ta phaigiai quyPt. van de phOi gher m1iy tinh Vl h~ t.hong truypn d¢ng di$n va l.iptrinh dicu khifn ht;- t.hong nhnm thim mH.n e~ic yell ci1u cong ngh~.24
  25. 25. C/ulflng 2xv LY TiNChuang nay trlnh bay khai qUIlt nhung viln oe cd ban ctm cong el,l toanhoc ;ot! dl,lng trong dieu khien so, do J: Xl! lY tm hii?u ,.;6 ),0 gom vi~e bieudi{;n t:~ic M thong roi rl:J.c, hillll t.ruyen o:~t eua hI) thong liJi n~e, phan deh h~t.hong rai r~c trong lllien z, bien d6i Fouripr rai r~c va h6 iQc s6.2.1 TiN HI/!:U VA HIt TH6NG ROI ~c2.1.1 Tin hieu tUong tl!Tn dri quen vbi d.c tin hifu co d9 dn v,l bien thihl lien tlc VI du di(;n~lP do dHQC tren qp nhi~t ngau cho t.a thong tin vll nhiet do moi tntong hiham cli~n lip lien tl,lc theo t.hai gian u(tJ, dien ,ip tren r:tfc nuiy phit toe chota th6ng tin VP tOc dQ true quay rfmg ill h(llH lien tlc thfo thai gian nit) Motcach tong quat. ta dinh nghia tin hi$u tuong tt ill ham co 00 ldn bien thienlien t.l,lc. Tren hlnh 2 la i.?l. dl:J.ng bieu dien cua tin hipu htdng t.V XltJ2,1.2 Tin hi~u iUqng tu h6ao t0)60403020oL-------------~tb)Hlnh 2.1 Tin hieu luang lu ia):. Tfn hie!) luang IW haa (b).
  26. 26. Neu bien d¢ cua tin hi~u liflfl t~c la rdi r~c til gQi tin hi~u do la tin hi~uluang tit hoa Tren hlnh 2.1b la d~ng bieu dien cua tin hi~u luqng tu hoa cuatin hi~u lien tlc.2.1.3 Tin hi,u rai r(lCNeu t~i tUng buoc thdi gian gQi la chu ky rai r~c T ~ ta X8.C d~nh dO Iancua tin hi$u ta duqc tin hi$u rai r;:te, neu bien d9 cua tin hi$u rai r;:te Iii lientlC (kh6ng dudC IU9ng tit hoa) thi tin hi~u do gQi lil tin hi~u Jay mAu. Hlnh2,2a la bigu dien tin hi~u lay mau.2.1.4 Tin hi~u soTin hi~u so lit tin hi~u dl1Qc rai rt;lc hoa ea bien so va bien dQ, khae voitin hi~u tuang tv la tin hi~u lien tlC v~ bien s6 va bien dO. Hlnh 2-2b bieudien t.in hi$u so x(nT).5D -.------- - -----:: ::-:l~i::I0) b)Hih 2.2. Tin hi~u lay m§.u (a); Tin hi~u s5 (b).2.2. CAC H¢ THONG XU LV TiN HI¢UTa thudng phan lo~i M thong xu Ii dn hi~u thea dn hi~u can xu If;- H~ thOng tuang tI! co cac d~i 111Qng vaa va ra I~ tin hi¢u tl1dng W. Hinh~L_ _~ba) b) ojHih 2.3. H~ thOng ttl(Jng tl.,l (a): He thein9 s6 (b); He theing xU Iy sO tOng quat (e).26
  27. 27. 2.3a lit Sd do M th6ng hidng tlj.- H~ th6ng s6 co cac d:;ti hiqng vao va ra lit tin hi~u s6. Hinh 2.3h la sddo h~ thong s6, trong so db nay ta nhi;ln thay neu h~ thong so duqc n6i vaih~ thong tuang tv thi t:;ti dau vao cua no phAi co b¢ d6i tuang tlj s6 ADC vadau ra phai co b¢ d6i s6 - ttfdng tv DAG H~ thong xit ly tin hi~u so t6ngquat cho tren hinh 2.3c.2.3 B1EV DlEN TiN H1J1:V.ROI R4CM¢t tin hi~u rai Tac dtfc;:lc bieu dWn bang day gia trt thljC ho!}c phuc. N~utin hieu do dtfc hlnh thanh hOi gia tri thtfc thl do 18. tin hi~u thtfc, con neudtfqc hinh ths.nh bai gia tr! phttc thi gOi IS. tin hi~u phuc.Tin hi~u rai r~c duac ky hieu liI. x(nT), trong do nTs }iI. bi€n d{)c l~p, nli1. so nguyen, T~ Iii chu ky lay m:lu De thu*n ti~n bien dien ta chmln hoa_ nTsbien dqc I~p nTs vai chu ky liiy mau Ts Wc Ii!. 1= n.,Ve m.lt toan hoc tin hi~u rai r~c x(n) duJc bieu dien nhu sau:~bOieU thuc toan hoc N I .:5 n .:5 N2x(n) = (2-1)n con l:;tivi dl!- 1 Day xung dan viTrong mien n day xung dan vi ducbii~u dien nhu sau:(2· 2)n 0Do thj cua o(n) cho tren hlnh 2-4.v{ du 2 Day buac nhay don v~Day buac nhay dan vi trong tni~nn dU;lc dinh nghia nhl1 sau:)In,.ou(n) = ~ 0 n 0(2·3)Do thj cua u(n) cho tren hinh 2.5.o(n)3-2-10 2 3Hlnh 2.4. Xung ddn vi.Urn)-I 0 nHlnh 2.5. Day bu6c nhay dCln vi.27
  28. 28. 2.4 H~: THONG TUYEN TiNH2.4.1 H~ thong xu Iy 56He thong xli ly s6 ULlQC di).C t.nrng bdi ll1(Jt toan tll T hlill nhiem VI biedoi day vao x(n) thanh day ra Y(UJ, ky hii}u nhu sau:TT[xlnj] = y ho;W xln} -~ yIn)N{;u h¢ thong Iii tuyi;n t.inh. t.min tll T thoa man nguyen Iy xep chongnghia 1:i:T[ax,tn) + bx~(n)] = RT[x,lnl] + hT[x~(n) = aYn) + by~(n) (2-4)a, b Iii h:li himg so hat ky:YI Is dap ting cua kich t.hich x I(n J:y~ La qlip ttng Ctm kfch thfch x2(n).2.4.2 Oap ung xung eLla h~ thong tuyen tinhM6t day xln) bllt k~ CD t.h{: dUde bi{iu diEm bang bi{iu thtic tong sau day:xxln) = Vx(kL(~(n - kl. h~--xNeu hi thong b tuy~;n dnhxylnl = T(xlnlJ == l[.2;xlkh-(n - kl],~~vi x(kl u(Jc lap vOi n nln tn coxy(n) == T[x(n 11 = 2:x(kIT[(~(n - kJ]k ---:0xYIn) = ~xlklhl..(nl ,j,,=-xh!-(nl gQi la dap tlng xung ([In he th6ng tuy(n tlnh.(2-51(2-61(2- 7)(2- 81(2-91Hp thong tuy{:n t.inh h:lt hir;n co hl(nl kh6ng rhl thlU)C viw k, con npuviii t,lc d6ng g:i6ng nhau d (,,1[ thni lli(lll kh:ll: nhau h~ th6ng sf cho d,ip dngkh,ic nhau hi h( thong pht,l thuill v:tO theri gian DCli voi hr· th6ng btit hjpn dap28
  29. 29. ung xung kh6ng ph! thu¢e vao thai diem xuat hien eua xung, hie do deh ehi1tprai rQ.e CUR tic d¢ng v6i d:,ip ling xung 5e eho tin hieu dati ra eua he thongh(n) = T[o(nl] thlh(n - k) = T[(~(n - kl] = h).,:(n)Phuong trlnh (2-9) dan den tong deh eh~p,ytnl = l:x(k)h(n - k)~ =--«T6ng cae deh eh~p thuang duqe viet ngan gon nhu san:yin) = x(n)*h(n), hoaeyin) = h(n)*x(n)(2-1m(2- III(2- 12)(2- 18)Ve phai cua (2.13) co dnh chiH giao hoan nghla la eel the viet (2.12) nhusau:,yin) = l:htklx(n - k) (2- 14)k =--«Ve m~t v~t Iy sIJ giao hoan nay co nghia Iii. neu dau vao eua h~ thong iii.x(n), dap ling xung ia h(n) va dau vao cua M thong ia htn), dap ung xung iiix(n) thl h~ th6ng se eho ra eung 1ll¢t dap ling dliCJe deh chi1tp bili hai ham.2.5 DAp liNG XUNG vA HAM TRUYEN DATDap ung xung hit) ia dap ung eua he thOng khi xung kieh thieh la DiraehaEm toan d!)c trung cho M thong rdi r~c Dap ung eua h~ thong d6i v6i mQibe d¢ng bat ky duqc X;:le djnh hb.ng cae bieu thlie tieh chap (2- 12), (2-14).Viee xac djnh dap ung xung trong nhicu truang hQp rat kho khan, do do ngudita thuong dung ham truyen dat de d~c trl!ng eho M thong. Vi~e xae dinhham truyen d~t elm h~ thong xung s~ duqe giai quyet. tron ven khi ta hieudi~n he thong va tin hi~u rai rae trong mien z.2.6 BlEU DIEN H~ TH6NG vA TIN III~U R(lI R4C TRONGMIEN Z2.6.1 Bieu di~n z thu~nTrang cae mue trt10e ta kh1tO sat tin hi~u va h~ thong rai rae trang miEmbien 86 d¢e ii1tp tIJ nhien Trang nhieu truong hqp each khao sat trIJc tiep nayg(lp nhfeu kh6 khan VI ht? thOng phlir: tiP va hieu qua kh6ng eao. Ta :311 d!ngphudng pha.p khao sat gian tier thong qua phep bien d6i lam nhiem vu ehuyen29
  30. 30. mi~n bi~n so dQe l~p sang milln mai.Bit!n doi z dong vai tro ·nhli bien d6iLaplace trong vi~e phan tfeh tin hi~uva M thong lien We vi the ta cangQi bien doi z Iii bien doi Laplace rairf,lc. Quan h~ giua mien n va mienz dU9C minh hQa tren hinh 2.6,2.6.2 Bi~n d6i zMlfln nbi@n doi z th14nbilln d6i z ngl1!;1cHlnh 2.8. Bien doi z.Bien d6i z eua tin hieu rai r~c x(n) trong lUren bien s6 dQc ioip tV nhienn 1a phep bien d6i tin hit?u X(z) trong mUm phue z theo hieu thue sauxX(z) = Lx(n)z (2-15)n=--XlTheo quan dietn toan ttl: ky hi~u ZT lit toan tu: bien d6i phue ta se co:ZT[x(n)] = X(z) hoacZTx(n) --..... X(z) (2-16)Bien doi z lit chuoi lay thua vo hl.ln. Chung se h9i t~ neu ehm5i (2-15) hi)it~. z Iii bien so phuc co the· viet dlioi d;:tng phan tht!c va phan ao:z = Re[z] + jlm[z].Vi n lay gia tri tit - 00 den +00 nen bien d6i z theo (2.15) gQi la bien doiz hai ph18. Neu n co gia tIi tit 0 den 00 ta co bien doi z mQt phia:X 1(z) = Lx(n)zn=OTrong m~t phang z co l1l~t vong tronllng voi Iz I = r = 1 gQi la vong tron ddnvj. Tron vong tron nay z = eIlJ. Hinh 2.7bieu difin vong tron ddn vi. Vong tron ddn0. d~e bi~t quan trong khi danh gia caed~c tinh eua M thong so dt!a vao vj tridi~m eve, diem zero (kh6ng) khi chungnam a trong hay ngoai vong tron don 0..Vi dlj.Cho tin hi~u roi r;:tc sau dAy:30(2-17)Re[Z]Hlnh 2.7. VOng trOn ddn vi.
  31. 31. {20x(n) = 0vai-oosn:s2voi n con I~iHa.y xac dinh bi@n d6i z hai phia, m9tphfa va mien hQi tl}. eua chung,TrIL loi:Tin hi~u x(n) co chieu dai [- , 2] =00 du:qc hieu dien tren do thi hinh 2.8,Theo dinh nghia bien doi z hai phlat.a co;D6i hien n = - III ta co:X(z) = 2:2-mzm + 2z-1 + 4z-2 + 1m=J,GQi Xj(z) = 2:Z1Tlzm yaj2 - zta dU:Qc:m=i,X(z) =-- + 1 + 2z-1+ 4z-2 vaj Iz I 2 va z 02 - ,Mien hOi tl cua X(z) ninn Mn trong Yang tron co ban kinh 2, trlt g6c toad¢. Bay gio ta tinh bien d6i Z Dl9t phla cua x(n): 2XJ(z) = Lx(n)z-rl = 2:2nz1l = 1 + 2z-1 + 4z-2n=1I nOMien hQi ty cua Xl(z) Ia toan b(l mat pha.ng Z tIU gOc t9a d¢ z = O.2.6.3 eVe va zero (Poles and Zeros)Trong tht,lc te ta thu:ong gi:lP bi~n deli z cho du:6i d!;lng ty s6 cua hai dathuc va nhU: yay X(z) lit ham huu ty eua z.X(z)N(z)D(z)(2-18)31
  32. 32. - Ta g[.Ji cac diem z =:; zr sao cho X(z,orJ = 0 ia cac zero cua X(z), dochlnh Iii. nghi(lll cua h( s6 N(z) Neu N(z) h da thtic b~c M ctm z thi X(z) coM zero.- Ta g[.Ji clic diem z =: zl~ sao cho X(zl~) = 00 IS. clic cic cua X(z), do litnghi~m cua mAu so D(z) Nell D(zJ la da thtic b~c N thi X(z) co N cic.Ta co the bieu di€-n X(z) dttai d~ng cl/c va zero:Neu N(z) la da thti:c h~~c Mella z:N(z) =: b + biZ +thi t.a co the: viet:MN(z) =: bM(z - zlIl)(z - zIl2l.··IZ - zOM) = bMfllz- ZUI.)vai zr Iii cae nghi~m cua N(z).Nell D(z) Ii da thlic bi1tc N Clla z:D(zl = a + alz +thi ta co the viet:vili zp/.. Iii cae nghi~m cua D(z)Tu do suy ra:X(z) =:;N(z)D(z)~ ------/=1v6iTrong 12-19) ta nMn thay co the xet tinh cMit cua X(Z) qua cac zero Z,,/,va cac clic Zpk. Trang lll(lt phang phlic cac cic dli(je bieu difin bang dau g:lchcheo (X) con cae zero dU{jc hieu di€!n bang cac khuy~n nM (0),32vi duCho x(nJ = OIn) + 30(n - 1) + 20(n - 2)Tim X(Zl. mien h9i tl va cae cie, zero ella X(Z).Trri liJi:X(Zl = L x(n)Zll =:; 1 + 3Z-1 + 2Z-2n=--
  33. 33. Mien hQi tl}. is taan b(l m~t phiing Z, trii Z = o.Tim qlc va zero:(Z + l)(Z + 2)X(Z) ~ Z-2(Z2 + 3Z + 2) ~ Z-(Z + l)(Z + 2) ~Z2X(Z) co hai zero t~i ZUI = -1va ZU2 = - 2 va tn(lt c~c kep t~i Zpl= Zp2 = O. Vj tri cac ct!c va zerocha tren hinh 2.9.-2z-,Im{ZIRe(Z)Thea d~nh nghla cua mien hQitl thi mien ht;li tlJ cua X(Z) khongchua cac Ctc vi t{li dci X(Z) khongxac djnh. Trang trl1ang h!;lp nayx(n) iii ehu6i huu h{ln X(Z) hOi tl}.trim taan llu)t pMng Z trii g6c t9ad(l IiI vj tri cac et!c Zpl va Zp2.Hlnh 2.9. Vi irf ella cl)c va zerO.2.6.4 Bien doi Z nguQcTim goe x(n) thea anh phlic X(Z) thea cong thuc:1x ~-- J X(z)zn - I dz, 2lrJ C(2- 20)c Is cluang cang khep kin baa quanh gOc t9a d(l ella mi;lt phiing z theachieu dl1!1ng va nam trang miElD h(li tl}. clla x(z).Trang tht!c te ta co ba phuong phap tinh bien doi z ngu!;lc:Tinh trt!c tiep deh phan (2-20) dung Ii thuyet th~ng du,Khai trien thitnh chuoi Illy thua thea z ho~e z-I,Khai trien thanh tong cae phdn thuc toi gUm.2.6.5 Cae tinh chat co ban cua bien doi Z- Tinh chiit tuyln tinh:Gia stt x(n) lit to hop tuyen tinh cua hai d!ly xl(n) va x~(nlx(n) = a1xl(n) + bxin) ; a, b lA cac hang s6 thi,ZT[x(n)] = L [axj(n) + bX2(n)]Z-n = aX1(Z) +bX2(ZIn =-0(2.21 I33
  34. 34. - Tinh chat treNeu yen) = x(n - n) thiZT[x(n - n,)] = Z-11nX(Z)_ Nhan day voi ham mu anNeu yen) == allx(n) thi bien deli Z la: oc Z ZZT[y(n)] = L anx(n)Z-n = L xn( - )-11 = x(- )n=-« n-« a aD::to ham cua bien dbi Z•dX(Z)dZ= L (-n)x(n)zn - In=-«NhAn ca. 2 ve voi -Z ta co:dX(Z). •-z -- = -Z L (_n)x(n)Z-n - I = Lx(n)Z-ndZ n=-« n=-ocTit day suy raZT[nx(n)]Tieh ehtjp eua hai daydXCZ)-ZdZNe·u day K,(n) Ill. deh ch(ip cua hai day x1(n) va x.2(n) nht1 sall:x.,(n) = xj(n) * xin)thl trong mien Z ta e6:X,(Z) = X,(Z).X,(Z)- Tich eua hai dayNeu X:-(n) Iil deh eua hai da.y x1(n) va x 2(n) nht1 sau:x}(n) = x j(n).x2(n)thi trong mien Z ta co quan M1 Z,X 3(Z) = 2-. fXj(v) Xi-)v- dVnJ vT!long quan eua Iwi tin hi¢u.(2- 22)(2- 23)(2- 24)(2-25)(2- 26)Hilln tt1dng quan cua hai tin hi~u x(n) va yen) dt1QC djnh nghiB nht1 sau:•rxy(n) = L x(m)ytm - n)Ill=34
  35. 35. thi trong mien Z ta co quan h¢1R,.(Z) ~ X(Z)Y(-). ZDinh Ij giri trt dew(2- 27)Cho ta gia trj tl.li g6c t9a d¢ cua m¢t day khi biet bien d6i Z cua no~ x(l)X(Z) = L x(n)Z = x(O) +--n_() Zhly lim eua X(Z) khi Z -+ Xl ta co:x(O) = lim X(Z).x(2)+-Z2+x(n)+--Z(2- 28)Ung d~ng cac tinh chat Cd han cua bien d5i Z ta eci co bang bien d6i Zthong dmg, giup chung ta tfnh nhanh han cae bien doi Z. Bang 2.1 lit biendoi Z cua cac hiull thong dmg.Urin/.: 2.1. IIlell dol Z th6nj,t dl.lllj,tM!n n Mi~n Z MiG hl;oi II,JJ(n} 1 Toan bi;o m4t ph.ing ZToan bi;o mal phoing Z~(n - no) Z-no troJ I~i 0 n6u no 0trW I;;l.i ~ neu no 0u(n} 1I 1- -l_Z- 1u(-n - I) 1 Z 1 I--l-Z-!nu(n) Z·, 1 z 1 I(I-Z Ianu(n) 1 1 z 1---l-aZ-1-au(-u - 1) 1 1 z 1 0I---[1-aZ-1I35
  36. 36. nau(n) IZ I :: aIZ I :: I1-2aZ-1coSOJo +a2Z- 21-az-lsin,~__ I IZI lal IL -, Z·,·________ ~1-2aZ cOSlllo+___l __._______2.7 B1£U DIEN CAC H~ TH6NG RDI RAC TRONG MIEN ZTil da bi~t trong mien n h$ thOng tuyen dnh bat bif:;n dl1t;Je d~e trl1ngbang dap ung x-ung h(n) nhung viee phan deh h$ thong nhieu khi g~p khcikhan nhu dnh dch eh~p, xet on djnh..De giai quyet khci khan trong mien n ta ehuyen each bieu di~n he th6ngsang mien Z va dua ra khai ni~m ve ham truyen d~t eua M thong raj r~e.2.7.1 Ham truyen diilt ella h~ th6ng rai r~eHam truy?m dl:lt ella he thong roi rle 11 bien d6i Z eUa dap ling xung vadl1;1e ky hi$U la H(Z)HIZ) ~ ZT[h(nl] ~y(z)X(Z)12- 29)Ta xet ham truyen dt:;lt ella mot M thong rai rl.le ctU1}e Ina ta bang phuongtrinh sai phan: quan h$ VaG - ra eua mOt M thong rai rl:lc tuyen t:inh bat biend119C eho hdi phuong trinh sai phan sau day:N ML a),y(n - k) = 2: b,x(n - r)kO r=1l(2- 30)Lay bi{{n d6i Z eua (2-30) ta dtt1}e36
  37. 37. Mk)] ~ ZT[2: bdn - ,)]1=0• N • M2: [ :2:ay(n - k)]Z-tln=--oo k=tl~ 2: [ 2: b,x(n - ,)]Z~n--;.o rUSU: dlng Hnh chat tr(!; va tlnh chAt tuy~n dnh eua bien d6i Z ta co:ML brZT[x(n - r)]1=0M2: b,ZX(Z)r=()MX(Z) 2: b,2°r=1ITir dci ta suy ra ham truy~n d~t H(Z) voi cae M s6 a],. va hr eua phlldngtrinh sai phfm nhll sau:Y(Z)H(Z) ~X(Z) N -L a~Z -],,=112.7.2 Bieu diEm ham truyen dl;lt thea cac clIC va z~rO(2-31)Cling gi6ng nhll tin hi~u rdi r~, ham truy~n d~t H(Z) eua mi)t M thongroi r~c cd the duqc bieu dilin bAng cae diem eVe va cae zero eua n6 nhu sau:MZIZ-I)n (1 -1=1H(Z) ~ CNZ Z-I-n (1 - pk )k= IMn (Z - ZrlCZN - Mr= I~Nn (Z - Zflk)k=l2.7.3 PMn tich h~ th6ng trong mien ZCae phan ttl: thl!C hi$n:- Phan tli tre(2- 32)37
  38. 38. GQi x(n) la dau va~, yen) Iii dau ra, quan M giua dati van va dati ra cuaphan tii: tre trong mi~n Z se iil:38yen) = x(n - 1)ZT[y(n)) = ZT[x(n - 1)] suy ra Y(Z) = Z-IX(Z) (2- 331Nhu vi).y phep tre trong miEm n dugc thay bang Z-l trong miEm Z.Tr{!n htnh 2.10a Iil so do kh6i phan tii: tre.- PM.n til. c¢ngG9i xl(n) iil cac dim vaa, yen) iil dau ra ta co quan M:My(n) = L Xj(n);:1Lay bien d6i Z ta co:MZT[y(nl] = ZT[2: xi(nl],;=1Msuy ra Y(Z) = L X1(Z)i=1Tren hl.nh 2.1Ob Ia sa do khoi cUa phan tu c¢ng- PM.n til nM.n vdi Mng s(i(2- 34)GQi x(n) hi dau vaa, a Iii hang so, yen) Iii dau ra ta co quan he sau:yen) = ax(n)Lay bien d6i Z ta coZT[Y(n)J = ZT[ax(n)1, suy ra Y(Z) = aX(Z)Hl.nh 2.10c la so do kh6i cua phan tu nhan voi hang s6XI (Z)l rX(z)aJx(z) ~IY(2) Z ix(z)Y(Z} olX(Z)c)+ •Y(Z)=I:X. (z)/.1 I-xc(zC:)-i!--:Cyrz-:J-_-,-xrz:C)(2- 35)Hlnh %.10 Phn tJ tra (a): Ph!n til eOng (b): Phn til nhan vdi hAng s6 (e).
  39. 39. 2.7.4 Phin tich h. th6ng rai r,cVi~c phan dch h~ th6ng rai rl.lC dl,ia trim nguyen tac chung sau day:- Tach M thong t6ng quat thanh cac M thOng nM han- Tim quan M ghep n6igilla cac kh6i nha han nay- Tim ham truy~n dl.ltH/ZJ cua cac khoi thanh phan- Tim ham truy~n dl.lt cuatorm M thong theo cac Hj(Z)va quy Iu~t ghep noLvi dl!.Xc!)HInti 2.11. H~ th6ng rilj rae c6 phan h~.Cho hi;! th6ng roi rl.lC co so db khoi tren hlnh 2.11. Tim ham truyl!n dl.ltchung cua M thOng thea H1(Z) vA H 2(Z).Trd liJi;Quan h~ H1(Z) va H 2(Z) 1a quan h~ phAn hM. D!)t bien ph! Y1(Z)Y,(Z) ~ X(Z) + H2(Z)Y(Z)Y(Z) H,(X)Y,(Z) ~ H,(Z)[X(Z) + H,(Z)Y(Zll= H1(Z)X(Z) + H 1(Z)H2(Z)Y(Z), tit do suy ra;Y(Z) [1 - H 1(Z)H2(Z») = H1(Z)X(Z), ta dUQc hiim truy~n dl.lt:Y(Z) H,(Z)H(Z) =-- ~X(Z) 1 - H,(Z)H,(Z)2.8 BltU mJi:N HI); TH6NG vA TIN HII);U RbI RAe TRONG MIiJ:NTAN 86Ta d.ii biet bang bien ddi Z co the nghien cuu M thong va tin hi~u riJi rl.lcva xac d,nh ham truyen dl.lt cua chung. Ta con co the su dlng mc)t c5ng CJ. toanh9C khac IS. bien ddi Fourier giup cho vi~ bieu di~n M thOng va tin hi~u rai rl.lctit mien bien so dt)c I~p n sang mien tan so liim tlC w. SI$ Him h~ gilla cae mn~nbieu di~n va cac phep bien dai dUQc minh hqa tron hinh 2.12.2.8.1 Bi4!n d6i Fourier rai r,c (DFT- Discrete Fourier Transform)Bien doi Fourier riJi rl.lC cua day ham tuan hoan x(n) co chu ky N dUQcdlnh nghIa nhu sau:39
  40. 40. 1. thllinMi€nZ, allan hf gida bien .J-,1.I dol z va bien aQi1 Fallrie.r1,Hlnh 2.12. Quan h(l gilia mfln n, Z va w.X(k) = ~l x(n)ei N knn=OL,Neu ta d~t W N = e-JN, ta co:2;1 2w~n = e1 Nl.;n, WN.......n == e1N I.;n(2- 36)Ta co thf viet l!;li bieu thrlc bien doi Fourier raj r~c (2- 36) nhu sau:N-IX(k) = L x(n)~n (2-37)n=OTa co the bieu diEm DFT Mng ky hi~u toan tii nhu sau:DFTx(n) - - - X(k)Bien doi Fourier raj r~c nguqc IDFT (Inverse Discrete Fourier Transform)duqc dinh nghta nhu sau:~(n) (2- 38)ho(lc~x(n) (2- 39)~Bien deli Fourier rai r~c 18. phep bien d6i th1Jc hi~n tuang ung mQt vectoX(k) trong mren am s6 rai r~c k voi mQt vectd xac d~nh trong mien bien s6n. Ban chilt cua DFT Iil bi~n d6i phl1c vi:10L,wNl.;n = ei N ==2n :,!;ncos- kn - jsm- kn.N N(2- 40)
  41. 41. Doi voi cac day kMng tuan hoan cd chi~u dai huu h~n, DFT duQc d~nhnghia nhu sau:X(k) ~N-lL x(n)w~nn=OOsksN-l(2-41)va kj hi~uo k con l~iIDFTX(k) - - -..... x(n)Bien ddi Fourier nguQc (lOFT) duQc djnh nghia1 N-J- L x(n)W-kn= N n=(I nX(k)Osk.:sN-l(2- 42)va kj hiiJ!uo k eon l::tiIDFTX(k) - - -..... x(n) ,o dAy ta gqi X(k) la phd rai r~c eua dn hi~u x(n), hieu dien duf:li d,;mg modunva argument ta co:X(k) ~ IX(k) Ie1~()~(k) ~ arg(X(k)]IX(k) I g9i la phd bien de) rai rac.p(k) Iii phd pha rai r~c.2.8.2 Bil1n dOi Fourier nhanh (FFT- Fast Fourier Transform)(2- 43)DFT trd thanh phan tu- quan trc;mg trong xU- Ii tin hi~u 36 hoi vi co thexay dl,lng nhtrng thu*t toan thl!C hien OFT rat hi~u qua, can it phep dnh,thl,lC hilim rat nhanh. Khi tinh OFT cho N diem me)t cach tntc tiep theo (2-41)din N phep nMm phuc va (N - 1) phep c9ng phuc. V~y de Hnh N h$ so OFTta dn thl!C hi~n N1 phep nhlin phuc va (N - 1)N phep cc)ng phuc.Nell chuy@n (2-41) sang d~ng lUQng giacX(k)N-1 2.n:nk 2-mk= Lx(n)[cos(-- ) - jsin(-- )]n=O N NN-] 2.n:nk 2.n:nk= L {(Re[x(n)]cos-- + Im[x(n)sin(-- )])n=O N N2nnk-j(Re[x(n)]sin(N) - Im[x(n)]cos2.n:nk(N I)} (2- 44)41
  42. 42. thi DFT co N diem dl1Qc Hnh vai 4Nl phep nhlin va 4(4N - 2) phep c(.lng.Ngoai ra con phai edt giu va dich ehuy~n day eac h~ s6 sin va cos tl10ng ungvai cac M s6 WNrU;. cling nhl1 2N mau th1C eua day vao x(n) phllc.Du cho co m¢t 56 ph€p dnh dl1Qc dOn giAn bOt nhO cac M 56 +1, °-1nhung dO phllc tf.lP khi dnh DFT tr1c tiep tang ty l(l vai NZ.Thu~t toan bien desi Fourier nhanh FFT cho phep giall1 bOt s6 IUQng phepHnh m6t cach dang ke. Co nhieu thu~t toan th1,1C hi~n FFT nhung dEm d1,latrim tu tuc:lng thl,{c hi~n DFT N di~m bang cac DFT cd so di~m tt hon vi khiHnh DFT trl,{c tiep do tinh chat cua cac ham lUQng giac ta dnh thira nhieuquan h~ theo chi s6 n va k.Ta nghien cuu tnot df.lng FFT dan giAn nhat gQi 1a thu~t toan cO s6 2phan chia thea thOi gian (Radix 2 Decimation in Time, R2DIT) de chi quatrinh tach DFT. Ten gQi cO so 2 de chi so diem DFT co th~ viet duai df.lngN = 21., vai L lit so nguyen thl1bng lay giua 3 va. lB. Cae phep Hen ket canthi€t trong qua trlnh tEi.ch dUQc thvc hi4;!n trong llliElO thai gian. Co th@, nh~ndUQc ket quA DFT N diem chan Mt ky bang to hQp ket qua. thl,{c hi(ln haiDFT N/2 diem, do v~y chi din thl,{C hi~n 2(N/2) = N l /2 phep dnh.Neu ta tien hitnh l~p If.li lien tiiip va nhieu phep tach doi, trong trubnghQp thu~t toan R2 bao gia ta cung co dUQc 21• thi cu6i cung ta chi din th1,1chi~n DFT nhci hai diem.Theo thUl).t toan R2DIT ta tach day vao x(n) phuc N diem thanh hai dAyx!(n) va. xz(n) co N/2 dient.x!(n) = x(2n), n = 0, 1, ..., (N/2) - 1x1(n) = x(2n + 1), n = 0, 1, , (N/2) - 1 (2-45)Theo djnh nghia DFT N diem, X(k) Ii Anh DFT etla x(n) dUQC viet duai dl;lng:X(k)N/l- != L x(2n)WNlnkn=()k = 0, 1, ., N - 1tlfl- 1+.1 x(2nn=Ovi WNl = (e12!IN)1 = e12JrI(NI1) = WN12do do (2-46) co. the dUQc viet theo da.y x1(n) va x2(n) nhu sau:42(2-46)(2- 47)(2- 48)
  43. 43. trong do X](k) + X2(k) la cac DFT dUQc chia dOi (N/2 dielu).Trang truong hQp dung thui).t toan FFT de dnh DFT N diem ta chi canNlogzN phep dnh phuc. Vi dl,l N = 1024 ta thl,lc hU;lD nhanh hem 100 Ian.Trong th!c te ml}t IC duy nhAt co tM th!c hi~n FFT 64 di~m con FFT 512di~m dUQc dl}t tr~n mc)t card duy nhat. Trong cac may dnh nha cd th~ chl.lYchudng trlnh FFT 1024 - 4096 diiim, con doi Val lll.ay tinh Ian 13. tren 16.000di£fm.2.9 BO LQC s62.9,1 Nguyen Iy qua trinh IQc tin hi~uXet Sd dEl chuc nang 19c tin hi~u Him t1c tren hinh 2 13.Tin hi~u x(t) dUQC lay mfi:u thea thai gian boi khcia dien tu: K, nhiP laymau T thanh tin hi4;!u lay mau x· (t).y(t~y(/~H1nll 2.13. Qua trinh Joe tin hi~u.Tin hi~u x-r(t) dua van mf.ch dch phan dung bang thoi gian xU: Iy cua bi)doi tudng h,t so ADC. Thai gian duy trl mau phai nha hdn thOi gian lay ma.uT. KM qua dau ra cua mJilch RC Ie. tin hi~u dUQC lay mAu va duy tri xT*(t).Trong bi;! ADC moi mA.u dUQc IUQng til: hoa va chuyen thanh mao 56 nhiphan cua r bit cua m6i 1111U se dUQC bieu di~n Mng 0 hol.lc 1 (kh6ng ho:;i.C cdxung).51,1 IUQng to hoa Iii vi~c gaD cho m6i mau mot gili tri duy nhat trong socAc muc gi.A tri cd the co dUQc .vB. M.ng 2f. Vi dl,l r = 10 cd 210 = 1024 mucgia tri.. M6i bit dUQc chuy~n qua mi;!t duang rieng sao cho mau duc;Jc ma hoaxwit hi~n a dau ra cua ADC duoi dl.lng tel hQp nhi phan dong thai d r duongra. Mdc cao nhat co the gbm r xung, muc thap nhat gam r gili trj. O. To rnacang dai trl:c la sO bit trong tu ctmg Ian thi dl? chinh xic cua mau cang Ian.43
  44. 44. Day miu mil hoa dllc;1c dua vao b(J loc 56 DF (Digital Filter), a do mildudc dnh toan theo cac phep toan c(mg, tru, nhlin, tr€! clla mot thu~t toanloc nao do. 0 dhu ra cua DF xuflt hi$n mil moi la tin hi$u s6 dil dllc;1C loc.Trong bO deli s6 - h1dng h! DAC mtii ma tac d(lng len mot nhorn cac khoadi~n tu dif!u khien vi~c c(lng cac muc di~n ap chuan cua mtii bit. Ket qua dAura Clla DAC ta duc;1C tin hit$u tttdng tv y.r(t) co d!;lng btiOc. Cu6i cung tin hi~uqua nwch bon cl!c co the coi la loc khoi ph~c, a do day tin hi$u tt1dng tv codl:lng bt10c h(t) duc;1c chuyen thanh tin hi~u ra lien tlC y(t).Luu y la Hit ca cae ho~t dong xli Iy cua mtii mau ph.ii nha hdn thai gianlay lllilU va can dam bao sU dong bO cho cae ho~t dQng ella cac khoa di~n ttl.1Van de nay duoc giai quyel hang day xung don dieu bOa tan s6 T t~o nenbang b¢ dao dong chuan.Vi T lit thong 56 chinh cua hO IQc s6 do do can chu y d~c bi~t den st! ondjnh tan 56 ella b¢ dao dOng nay.Uu diem ca bim cua bi? loc so la co d(J tin c~y cao, st! on djnh cua thong56 ma cac b¢ Joc tuong ttl kh6ng the eo dUc;1c.2.9.2 BO xU- Iy tin hi9U 56 D$PB¢ xtr Iy tin hi~u s6 DSP (Digital Signal Processor) Iii b¢ xli Iy chuyendlng duqe thi€t ke rieng cho vi~e tht!e hi$n eae I$nh s6 hoc, do do thvc hi~nnhanh hdn bo xii Iy thong dlng. Chuang trlnh cua chung sii dlng cac I$nhs6 hQc nhieu hdn l$nh truyfm dli li~u va vao-ra. Noi chung DSP lay mdu tinhi~lU vao sau do ehuyen qua b¢ IOc thlJng thAp rai tinh twin cae dau ra moLCac tin hi~u ra nAy den h1Qt chung duqc chuyen sang b6 doi s6-tttc1ng tv DAC.Cac thao tac chinh lit phep nhan va tich liiy.Theo djnh ly lAy ma.u Nyquist llloi th6ng tin tUdng tt! co the duqc kh6iphle DI?U thn s6 liiy mAu ba.ng ho~c Ion hdn hai Ian tan s6 cao nhM cua tinhi$u ban dau.Cae tin hi$u thl!C co thanh phlln thn s6 cao nhat tuang d6i nha. DO ri?ngdAi BW (Band Width) dUQc djnh nghfa bang tan s6 thitnh phan tin hi~u bangm(:lt nu-a cong suat, 0,707 bi~n d(:l cua thRnh phlln m~t chi~u. DO r¢ng daiduqc Hnh gan dung theo phudng trinh:0,35fl-W = (2-49)t,44
  45. 45. tr In thai gian suan tang eua tin hh?u, dUQc xac djnh tll: 0,1 den 0,9 trj s6 tinhi~u cuoi, cho phep h~ thong nMn dUQc it nhat 5 mliu trong khi 11111c tin hi~utang hOl;1c giam nhanh.B¢ IQc so dap ung xung toi h~n FIR (Finite Impulse Response Filter) cobieu thlie dau ra:yen) = bx(n) + bjx(n - 1) +b2x(n - 2) +Cr dayM la s6 Ian IS:y mliu qlc d(~iyen) la dati ra clla milu d t.hi:li gian nx(k) la dau vao clla milu t.hai gian kb(k) Iii. h$ s6 clla bl? lQc ella !lUlU thai gian kMyen) = L bkx(n - k)k=1I+bMx(n - M) (2- 50)(2-51)Trang chuong 6 ta se nghi?n cuu ky cach thtje hi~n philn cung va chudngtrinh phan melll eho FFT V~ DSP2.10 LAY MAU vA LI1U GIU TiN HIEU s6Trang he thOng dieu khien so ctlc milu dtiQC hlY tti cac d~i hiQng lien t.lenhu di$n ap, dong di$n, toc do.. Vai tro clia ho lay mfiu lit bien doi tin hi~lIlien tlC thanh tin hi$u rai r~c. Trang bi? lay mall tiep diem dong l.;ti de tinhieu di qua trong khoimg tMi ginn lay mau. Trang thlc t.EO khoang tMi gianlay mau nlt ngan so voi hang s6 thai gian Clla cae t.hi:li diem 0, T, 2T .., t.rongdo T la chu ky fiy mau. Giiia hai Ian lay mau lien tiep L¢ lay mau khongnh*n tni?t t.hOng t.in nao Phan tl1 Iuu gifi se. chuyen deii tin hi~u da dugc laymiu thanh tIn hi~u gan lien tl,lc, ti$m c;ln voi tin hi{lu tnioc khi no dUde laymau. Phan t1 hiu giil don gi~m nh.1t. Iii. phan tl1 chuyen dOl tin hi$u lay miluthanh tin hi$u b~c thang va khong doi giila hai thai diem Jay mau. Do 1;phan tu.: do~n thang, ve toan hQC duoe bietl djen bang da thu:c bt:i-c khong nengQi Iii. luu giii b*e kh6ng ZOH (Zero - Order - Hold), co ham truyen dJ;l.tZOH(s). Tren hinh 2.15 la sf1 do Jay mau va luu gilt tfn hi$llPhan t.11 luu git co Lll~e dnh ella bi? IQc thong thap, hlm trdn tin hi~u laylllaU x(t) In llli?t day xung thanh tin hif.u xh(tl co bUm do khong doi Hnh tll:thai diem hlY mau den t.hai diem lay mli.u m0io ~ t. T. (2- 52)45
  46. 46. Phlln tu luu giu cd chuc na.ng dch pha.n tin hi~u xung x*(t) giua hai thaidiem lay miu k@ tiep nhau vi dch phiin mQt xung cho ta tnQt hang so. N~ucoi dau ra cua b) lay I1l:lU Ja m~t chuoi xung tn;mg luqng, ta cd th~ I~p duqcquan M giua tin hieu lien tl,lC va dau ra cua bQ Hiy mAu Iii:x (t) = 0T(tl.x(t)0T (t) la m¢t chudi xung ddn vj.(2- 53)Co the coi b6 lay llU1U iA b¢ dieu bien voi dau vao III tin hieu dieu bienx(t) va chuoi xung ddn vi h1 song tnang nhu tren hlnh 2.16.Bieu thuc cua chuoi xung ddn vi•Or ~ 2: OCt - kT) (2- 54)~=-xtrong do o{t - kT) Iii lll¢t xung ddn vi xuat hiifn t~i thdi diem t = kT, nhuvay tin hi~u da lay llU1U co the dllqc viet Iii:16x(t) ~2: x(t).O(t - kT), ho~c (2-55)~=~x (t) ~2: x(kt.J.o(t - kTJ (2- 56)k=--oo, 4r--~--~~, fll! !!, , ,I0 0 -2 t-, _4 L ___-L_ _ ,0 w 10 30 0 10 20 30oJ JI --r-~i 12f ,ofVj -=-----;~ ZOH~,,~1.L dJ, .. - - - - - -, ,0 W 10 30OJHlnh 2.Hi. Uy mau va h.1u gili lin hi~ua) Tin hi~u VilO x(I): b) Tin hi~u lay mau x·(ll, c) Tin hi~u ra xll(I):d) Sd d6 lily mau va loJu gioJ.
  47. 47. 89 lay ma~• • •r-----------------,lOT(t),, ,, ,, ,, ix,,(t.I(f} ID/eu bi€n xllng ,, ,, ,, ,-3T -2T -T 0 T 2T 3T tL _________________ JaJHlnh 2-18. Quan niem ve b~ lay maueo) Chu6i )(ung dOri vi, b) B¢ lay m~u.b)Vi bi~n de? cua xung Dirac 18. vo cung Ian nen de thu~)n ti¢n ta dung chieucao mui t~n de chi cU:bng d~ hay di~n deh cae hiull xung nay Tren hinh 2.16achiEm caa mui t~n tr~n d6 thi x~(t) hldng ling v6i uti Ion cua moi gia tri dl1QcIiiy lllall tit x(t). Trang thlCc tii da s6 cae ham thCfi gian lay gia tr~ khOng nhihan goc 0, do do bieu thtic elm t.in hi~u lay mAu Ill:•x(t) :: L x(t).Mt - kT) (2-57)kl1Dap ting xung iii xung co chieu caa 1 va chieu n)ng T sec. Bieu thuc euadap ling xung hih(t) = !(t) - I(t - T) (2-58)Ham truyen iil anh Laplace cua p(t)ZOH(p) = {h(tl) = J[1(t) - l(t - T)]e1I _dt = (1 - e11I)ip (2-59)Bang 2.2 cho ta dap ung xung cua tin hi~u hlY mdu va bien d6i Z cua no.47
  48. 48. I~I,~Io~.I0- rU•I ~ i--~.1-~I- I CI, IC-I-0OII ~~~~ ~~ ~N,I C -0, -. ~ ~!:~.=~I~ =I ,f--I =/I~~I-I,~j~~~,~.~- !-- :1 ,i t~ ~~ l- eI: It:- F- F-tI~,~II.:1 - ~- ~0 ~. ~I e N.1 IT•2 03~I~~f~,I ~ ••.=rnI iii;.,~I ~.I ••I ·01.1 cr .,I,N -I~I N 0I••••48
  49. 49. ~go•h,,•!.+:2 !./•I---------+~+•,,o•........ ----J•=-.=.==~I49
  50. 50. Chuung 3MO HINH MAY DIEN VATHIET Bl BIEN 061Vi$c nghil!n cuu cac dnh ch.it cua may di~n quay va thiet bi bien d6i bandAn cOng sua:t b che dt;! qua dQ nh~m m1,lc dich danh gia kha nang chju d~ngcua thiet bi voi nhung ung sua:t Ian Ie di(ln, nhi(lt va cO trong di~u ki~n lamvi(lc kM.c nghi¢t coa che di? qua dO, m$t khac ding nham nh*n biet cac quylu~t cua thiet bi dieu khii!n nham duy tri ch€ d¢ lam vi~c djnh nl1.1c cua maydi~n va thiet bi bien d6i.Th~dq~_M_~~~6~~_*~~~mvi¢c ache d¢ dinh muc. Tuy nhilin thiet b! di~n can phAi san sang lam vi(lctrong cac di~u kien ba:t thudng nhu xuat hi(ln ngan m~ch, Old may, .... Cae ch€dO nay chu yeu dAn den ung suat ca nhu I~c di~n dong tron dAy quan, cl,l thetrong dau dAy quan, momen tren tt1,lC dt;!ng co, ung suat nhi~t.Vi¢c nh~n bi~t ham truYflD coa d6i tu(;mg di~u khien Ia can thiet khi thietke cae thiet bi diEm khien. De nghien cUu may di(ln va thiet bj bU!n d6i trongqua trinh liun vi¢c binh thuong ciing nha b ch€ dO qua de) can xay d~ng mOhlnh toaD hqc cho may di~n va thiet bi bien d6i. Tn..atc tien ta nghien cUu 016hinh CI che de) lien tl,lc sau do 18. 016 blnb Q cbe di? rai r:;tc.3.1 cAc GIA TIUih DON GIAND~ nghien cUu may dif!D d ch€ dQ qua dQ ta dU:a ra mi?t s6 gia thiet dangian hoa sau day:3.1.1 May di~n khong bao hoa, quan h~ giiia dong di~n V8tu thong 8 tuyen tfnh3.1.2 Phin bd hinh sinCac day qua:n b6 tri tren m(l.ch tit cua may di~n quay t~o nen suc tit d9ngphAn b6 chu ky hinh sin, nghia iii chi chu y tai st! pM.n b6 khOng gian cuadieu hoa b*c nha:t.50
  51. 51. 3.1.3 MIliCb thOng 86 t(llp trungGia thil§t ti€t di~n eua dAy qUlln diI nM de m~t d¢ dong di¢n phan b6deu, k€t cau d6i xllng.3.2 ruM TAT NHUNG VAN DE co BAN vE sue DI~N DoNG vAM()MEN DI~N Til eVA H~ TH6NG DAy QUAN co DONG DI~Neay QUAKhi n m;;teh (eo hi;! so t1! eam Lj) dong di¢n ij ch~y qua co liAn h¢ ho camthe hi¢n qua h~ s6 h6 cam Mjk tit thOng eua day quan duqc xae djnh Mi bieuthueVi = Ljij + L Mjkik (3- 1)k = Ik ,.. iSuc di¢n dt)ng cam ling (s.d.d.) eltrong day qmtn du;lC xitc dinh theo bieuthlic:(3- 2)Dl.1o ham (3- 2) theo t va the van (3-0 ta thay co 2 I01;li sue di~n d¢ngcam ung trong dAy quan:- N€u L I, Mjk ij va ik kh6ng doi, trong truang h;1p eho phep ehuyen d¢ngquay theo goc e s~ xuat hi~n suc di/?n d¢ng quay:(JVl deilf} dt- Neu Lj, Mik i, va i~ kh6ng d5i, gOc quay {} khbng doi, tu thong moevang chi bien thiE!D theo thai gian ta co sue di~n d9ng biPn tip:Suc di~n d9ng cam ung trong day quan i se Iii:iJV1 d(Je· =-~II i!f} at(3- 3)M6men dien tit:1 1 ,IL i=~Ii~ +2 j ,j(j(3.4)51
  52. 52. fa nMn th.iy sl1 bien dai nang il1Qng di~n tu thanh cd nang va ngl1Qc IJ;l.ichi xay ra khi trong bieu thuc cua cbng suat di~n ttl co m~t thanh phan sucdi~n d(lng quay.Trang cac ap dv.ng sau nay ta coj mamen di~n tu co chiEm dUdng, gQi MllIii mbmen dang cd va Me la mamen can Phudng trinh chuyen c1¢ng cUa d(mgcd co the viet la:(3- 5).J la mamen qmin tinh eua phan quay.3.., MO HINH eVA MAy DIJ1:N MQT eHIE:U3.3.1 Sa db va phUong trinh t6ng quat eua may di~n mQt ehieuSd do tong quat cua may di~n mOt chUm cha tren hinh 3.la- frlc Od (trlc dqc) ung voi tTlC tu clla day qmln kich tU, thuong kyhj~u bang chu f- Trlc Oq (tll,lC ngang) ung vai trlc ttl clla m¢t so day qutln phl co d~nh(vi dl day quan bu) ta hinh dung nhu m(lt day quan ky hi~u 13 g.TrElll trlc ngang Oq thl10ng d~t chbi di~n A, B cia phan ung. Luu y nlnggiua chai dien A va B ph3.n {jng tlic d¢ng nhu lll¢t cu¢n day co trlc tU luonhuang thea trlc ngang Oq, tren hinh 3.lb bieu diEin chieu dong di~n phAnung co chiEm ngl1Qc nhau so vaj duong qua chai dien khi cac thanh dAn philnung cnuyen d¢ng. Lay chfeu quay theo chieu kim d6ng ho vaj quy udc dau:Dong di$n dUdng t~o nlm trong day quan cua no ttt th6ng dUdng,Suc tis d¢ng d1./dng tJ;l.O nen dong di~n dtldng trong day quan.Quy uac dau nay dung cho cac may di~n quay, doi val di~n ap cae dayquan dung yen du~c coi nhu tai, day quan phan ung nhl1 lmiy phat.Cac thOng s6 d(c tnmg cha lUay di~n m(lt chi~u:ai Di¢n trd uiL dien cam eli,a day quanday quan klah ttl trlc dqc d: Rfva L[day qUlin co dinh (day quan bU.) ngang trle q: Rg va Lgday quan phan ung giua hai eha! di~n A va B: Rq va Llb) Ho aim giiJa hai day qudn theo tr,!c ngang q: Mgcl
  53. 53. c) H6 cam gi(la cu¢n k{ch til f va phan ling n~u choi dien dgt theo trllCdQc ad: Mfd, neu chi cd dong di$n klch tu if thl chi cd tU thong 1fu = MfdifQuan h(! giua tit thong va dong dif!n lit:~d !Mi,=~r,L,i Iflql : Ll ;Mgq iq ,, ,,1/g Mgq Lg i g :Cae phuong trinh di~n cua 3 dAy quan 18.:B0i,A,,11Jd~r+--dtd~~+--dt1d,_t~1cit~wci,I, dI(3- 6)(3- 7)(3- 8)800 @ ~wc09 @09 @09 @09 0@A1® Dong Olin ti) ngobi® 00119 Ji~(I fif frong rob)Hlnh 3.1. So do mAy di~!n mQI ehiEtua) Sd do t6ng quat va (]uy llilc ch(eu cae dtlng dien; b) Chleu dong dien phan LIng.53
  54. 54. VI cac day qwln r va g co dinh so vcJi M tQa dq (Od, Oq) nen hai phuongtrinh dA.u tien cua (3-8) chi xuat hi~n s.d.d. bi~n ap. Day quan phan ung giiiahai ch6i di(m A 1a B tac d(lng nhu: cul)n day tr1,lc ttt Oq t~a nen sdd bien apkhi tit thOng bi~n thien thea trlc nay, ngoai ra vi day qUAn chuyen d¢ng sexuilt hi~n sdd quay.eqr ::= wr~.1 = Mrdw,lr·Vi bO qua bfio bOa ta coi sdd quay ti l~ thu~n vcJi t6c dO quay va dongdi~n kich tii.C6ng suat Wc thai do may di(ln m¢t chieu 1:.:;1.0 nen:dJ/! .. R 0 • 4Pe = Uqlll ::= - qlq~ - Iq dt + (3- 9)C6ng suat tuc thai gbm 3 thanh philn:Thanh phan dau tiEm Rliq2 ling vcJi t6n hao Joule,Thanh phAn thu hai ung voi bien thlen cua nAng hlc;Jng ttt truClng dchhly,Thanh phan thli ba1a cong suat ca.3.3.2 May di(!n mQtchieu tong quatXet cau truc may di~nnu)t chieu t6ng quat trenhinh 3.2, trong do co 2 d6ichtH di~n:Ad va Bd thea trlc clQcOdAq va Oq thea tr1,lcngang OqDi$n tra phan ungkh6ng d6i thea tr1,lc Od vaOq:{B,+-B,/ ;(we dfII Ad/ I i Iv,1/ ill-./ IA,4-r: - i,~1 f:::p9H In h 3.2. So do may dien mOt chieu tOng qulU.Ttl m1C 3.3.1 ta !my ra (.3.C phuong trinh di~n tii54d
  55. 55. (3-10)(3-11)RrifdVrUf~+-dtRgigdl/gu, ~+--dt (3-12)-RiddVduJ~- Wrfqdtuq~ -Riq -dVy+ w,rllfddtHai phuong trlnh euoi eua (3-12) khae dau Ie. do gOe quay eho pbep ehuyentit tit thOng trl:le l/q theo chi~u duong cua sdd quay v(:!i edr.C6ng suat di~n tuc thbi clla may di~n m9t ehieuMamen di$n tu gAn voicac suc di~n dQng quay ehiarna toc d¢Mdt =Idiq l/qid (3-13)Lo~i may di~n mQt chieunay ia may di~n co tu thOngvuong goc thuong dUng trong1119t s6 may di~n m()t chi~ud~e bi~t nhu may di~n khueehdl,ii. Ngay nay do s~ pbat trieneua di~n tit dmg suat nguoi takhtmg dung cac may di$nkhuech d~i n[ta, nhung Mphuong trl.nh (3-12) thl,tc tekh6ng thay deli doi vai cac lo~i(j dlu +dto. d¥lI ),--lJ dtdHinh 3.3. May di~n mOt chi~u khOng bu.55
  56. 56. may di(!r. quay khac, Cl the ii dCii vai may di~n xoay chipuTren cac trlc dqc va ngang ta con cd the thay cac day quan kich ttl noitiEfp hoac song song, do ia cac day quan biI va day quan d6i chieu.3.3.3 Anh huang eua day qun buTa sf! nghipn cuu Sd hwc anh hliong ella day quan biI phan ting phan tingd6i voi tinh nang cua may di~n tn9t chieu 0- che d¢ qua d9.u) May dUn khiinK hflKhi khbng co day qmn g sCI do t.ong qmit hinh 8.2 dan toi hinh 3.3. HI?phl1C1ng trinh tu (3-6) den (:3-9) tro thanh:dilL--I tltb) Muy difn mljl chif?1I C(; biiIJhcin lin/.! philn linKDe biI phan ung phil.n ung,day quan g phii duqc mac nbiW3p voi day quan q sao cho dongdip,n ig va ill bang nhau va traidau. Theo hinh 3,4 ta thay xuathi¢n di~n ap 1110i tren cac qtcu ::= U + uq q ;:ig = -illThe vao cae phuClng trinh tU(3- 6) den (3- 9) ta dUQc;dilL--I dtulj = -(RI + Rg)~1 - (LI~1i = i, ,(3- 14)dHlnh 3.4. May di€m mOl chieu c6 bu.(3- 15)
  57. 57. Ta nhi;t.n thay h~ phuong trinh (3-15) ding cimg nguon g6e phuong tdnh(3-14), Vi$e bu kh6ng liun thay doi de quy lu~t bi~n thiE!D ve djnh tinh, nhu:ngVEo ujnh IU9ng bu hQp Iy se tao n€mLI + L~ - 2M;:1 LIdo v~)y bil se !fun gi8.ll1 d;i.ng kP ui~n cam philn dng, do do lam gdll1 hang ,,()thili gian d che dQ qua do. Tii do suy fa ket lu(O: Du Cel hil pMn ling philnling hay khong thlmay dien m(Jt ehicu ciing tmln theo h~ phuong trinh (3.14Jnhung khi hu phan ung phan ring ph/ii them R)! vilO ~I VII thay the LI bangm6t uit?n cam co gia tri nha han nhieu.3.3.4 Dieu ehinh t6e dO dong ea mot chieu bing tile dong len di~nap phsn lingTiep thea ta xet 11lQt VI d1 ve vi~c diell chinh t{)e 16 d(mg co mot chieuDat. RLR)! + RIL+L-2MI )! ~1Cae phuong trinh (3-14) lip d1,lng cho eh0 d¢ d{mg cd, (oi 11 va am. Nellta kh6ng thay d6i di~n lip kich tu, phLidng trinh dau tien chung to dong di$ni l kh6ng thay dtii va bang ghi trj dong kich tU han uihl II. H~ thong ph:!.ituan thea phtiong t.rlnh 13-111Vi i l= II kh6ng deli, h~ tMng (3-111 h tuyen tlnh va eo the up d1,lnghien doi Laplace cho cae E;ai phan. do d6 dan dfin phuong trlnh sai phanL.Uq(pl = MtdII(/~w/PJ - (R + LplL.illp)t..Crn(p) = ,fpL.(u,(p) + Mtilt,,~ii(piGi1li h~ phuong trinh sai philn my tim duqc L.UJ,.(pl Vl1 t..i (p) thea hjPnIMfdIIL.Ulip)(MldII,)~ + JpfR + Lp)-JpL.Uq(p) + MluIIc-..Mc(pJ= (MldItt)2 + Jp(R + Lp)} (3-16)Phuong trinh 13-16 cho ta anh htidng eua t..l:I(p) V~l L.ML(p) den toe u)va dong elien phEW ling. Thea quan dipm drilu ehinh ta co t.he nghien eriu ham57
  58. 58. truyfm gifta t6c dO v~ di~n ap phhn ung. Vi dl n~u gift thi~t m6men kMngdeli va phtm ung phan ung dUQc biI het (L = 0) ham truy~n trd nen bi€u thtlcddn giAn:vai~/p) ki~6.Ull(p) 1 + TmP1ki =~~M ld l f(1T m HI. hAng so thai gian Cd eua dCJng cd* Vi d1,l bang so cho df,ie tinh d(mg cd va cua taidi~n tra va di~n cam philn dng (gia thi€t co biI):R = 0,05Q, L = 1 mHmcnnen qUlin tfnh cua phan quay J = 100 kg.m2Dieu ki$n dau:Ull = 200V, IqCl = -200A, Wro = 47,5 rad/stao nlm hang so Mtu1f( = 4 WbNghUm cUu bien thien toe d): bat dau ttl eht de? nay ta giam dOt ngqtdi~n lip Uq20V20pcon momen ed v§.n kh6ng d6i 6.Mc(p) = 0Thea phudng trinh (3-16) ta co the tlm dl1(JC gOe t9a d) va dong dii;lnthea thai gianw/t) = 42,5 + 5,4exp(-3,4t) - 0,4exp(-46,6t)i (t) = -200 + 464[exp(-3,4t) - exp(-46,6t)].qCae quy l~t bUln thi~n n~y dU(Jc ve trfm hinh 3- 5, ta nh~n thay mngbien thien di~n ap 20V lam xu:H hi~n dong di$n nguQc, do do sinh ra snhhuang giSlll t6e Ian nhung kh6ng vu(Jt qua gia tr! dlnh mde eua no. Sau khixmlt hi~n bien thien dong di~n vaj hang s6 thai gian L/R, dong di~n va toed) trd ve gia trj on d!nh vai hAng so thCli gian cd bang:RJ58
  59. 59. Mo hinh toan h9C cllamay di~n mQt chiim nghi€mcuu d tren cho phep giAiquy~t van de dnh tOlin h~th6ng di~u khien, ngay Cfttruong hgp dQng Cd d1igcn6i voi bl? chinh hiu co dieukhignD;;ic dnh Clla may dit?nm9t chi~u Cl the la muc bilphAn ung phan ung co anhhuang rat Ion den d~c dnhclla b¢ chinh hlu va co thedanh gia anh huang nay~;-•--341,545.02.540.0:-..- -- - -- -- -- - --L-i==mng 1110 hinh toan h9C clla Hlnh 3-11, T1Sc dQ vii dOng di~n phttn Llng dQng cd kfchmay di(m mqt chieu tLJ dOc lap khi dOt nhien bign thien dii!!n ap phn ling.3.4 MO HiNH ToAN H«;Ie eVA MAy mj):N XOAY eHlEU3.4.1 Sa db may di, xoay chieuXet may di~n quay ba pha (dong bQ ho;:ic kh6ng dong bQ) o;tato la nlt;1ch2nti1 t;:to ttl truong quay co b6 tri 3 day quan a, b, c co trlc tit l~ch nhau :3doi voi may hai ct,(c (p 1) nhu hinh 3.6aMay di~n co the thu9C lo~i bat ky, 0 day kh6ng the hi~n day quan roto.Quan he gii1a tit th6ng va dong di~n la ham so clla goc quay dl).c trung chov1 tri tuc thoi Clla roto d6i vai stato. Ta co the don giAn hoa vi~c nghi€lfi cuumay di~n xoay chieu ba pha tht,(c Mng phep thay doi bien 0;6 gOi la bien doiPark bieu dilin may dien tht,(c theo hal trlc toa dq vuong goc (Od va Oq)Trlc Od (trl,lc doc) lam voi pha ft goc f) va tIl:lC ngang Oq ch(lm sau Od nlNgoc n!2 (hinh 3.6b).3.4.2 Bien d6i ParkDuo; dt;1ng ma tr~n st,( thay doi bien theo h~ toa d(l d, q va t9ft d¢ tt,( nhiena, b, c d1iQc bieu di~n bang phuong trlnh:59
  60. 60. b dd8o)«[---=---t---v;; i 9aJbJHlnh 3.8 Sd do may dien tv trudng quaya) Day qua:n IhllC a, b va c: b) Day quoin giA wdng d va q.2,. 4cos H cos (0-3) cos ((J -)32 2. 4:1sinO sinO? - ---I sioW -) il:l :1(3- 17)1 1 12 2 2ied day ilr dong di(m dQc trlciq- dong di$n ngang truei,,- thanh phan dong diE1n tliang dliOng voj thanh philn thti tu kh6ng, dehi thong- (3.17) co tinh chfit nghjch d~lO, nhung chi khi i co l1l:Lt, tcing i +ii + ie khac kh6ng. Ta co the viet phuong tdnh (3-] 7) duoi Jl).ng rut g9n:i = AidI Ill((3-18)A Iii lila trt~n Park.Ngh~ch daD etta (3-17) cho t.a t;m d¢ thW: thea t9a do vuong gac:11COS H sinf.i 1 id,. ii cos (H- y,) sm(AT) 1 i (3- 19)I4, 4JTie eos (H - sin(A3- - ) 1 i3 60
  61. 61. hoac du6i dl;l-ng rut g9n:i = KJi (8-20)ahe dqNeu chu y den cac h~ so clla hai dong dau tien Clla (:~-17) va hai c9t daHelta (3-19) ta nhi).n thily cac day quan a, b, c xep chOng tao nfm suc til d¢ngphiin b6 hinh sin thea fJ co cVc dl;l-i lan h1;1t trimg v(ji truc pha Oa, Ob, Oc cothe dll~lC thay the bAng hai cu¢n day gia tuimg d va q co tr1,lc ttl ludn c6 djnhso v6i cac tr1,lc Od va Oq nhll hinh 3.6b.S1 thay doi bien so cling dU;1C ap d1,lng cho hEI thOng difn fip ua ub Ucva til thong ~a ~h ~, cua stat.o. Cae phl1dng trinh tong quat cd d:tng:ud !~Aual,,, (3- 21)U]l~A-I udI(3- 22)~)tlt] ~A~!K (3-23)~;IIc K ~ dq(3-2413.4.3 Phuong trinh ParkKh6ng ph1,l thu¢c v~lo (illY quan rota, ba day quan tren hinh 3.6a t.uanthea cac phl1dng trinh tong quat:dlldt(3-25)cit. d~cltl, = - Rll - dtR la di~n tro 1119t pha Clla stata. Ta viet dl10i dl;l-ng ma tr;.i.n tong quatciuhc = - RiI. - -dt~rabcAp dl:mg bien doi Park cho he phlldng trinh (3-20), (3-21l va (3-24) tadllQCTa nh~n thaydA-(A-I)IjIiIdt61
  62. 62. 0 -1 0d ,A ~ (A-I) 1 0 o idt0:0 0ttl do, b~ng each khai tri~n ta co:dVd daill - VJq~dededtdV1dt+ 1oJ--dt(3.26)U o = -R) -dl/dt3 phuong trinh (3-26) t:;10 nell cae phuong trinh Park.Ta nMn thay co sl,t triIng hQp hoan toan cua hai phlwng trinh dau tienvcri hai phuong trinh cuni cua lluiy di$n 1119t chieu t6ng quat (3-12), chi codBdieu khac Iii d day dt kh6ng phai Ia toe dq quay r Vi day qmlD gia tllong dva q cua hinh 3.6b tlldng tv day quan phAn ung cua may di$n mcit chiflu: caetr1,1c tit co dinh so voi toa do t~o nell boi tr1,1c Od va Oq nhllng thanh dtlnchuyen d(mg so voi tr1,1c t9a d9. fa co the di den k€t !u:)n: Bien d6i Park d6ivoi day quan ba pha a, b, c ding gi6ng nhU: bien doi cua c6lectd len phlln ungnuiy di~n m9t chieu.623.4.4 COng su4t va mOmenC6ng suat tue thbi cua day quan a, b, q a mQi thai dUl11l bangPc = u)a + uj,iL, + ucicbang bifin d6i Park theo (3-20) va (3-22) ta tim dUQc ve thu hai3Pc =T(U,}d + uqiq + 2u,~(,).Khi lilt d1,lng phuong trinh (3-26) ta co:3+-(w.i2 or U IId1/) id) - .I dt3 . d~d(1- +2 dt. dVq, -+4 dtTa nh~n thay trong bieu thuc Pl co 3 thanh phhn:d,2· --) dt(327)
  63. 63. 3 ,thanh philn - -R (i l + i + i}l bieu dien ton haa Joule trong philn2 U IlJ:ng3 dVJ dV dVthanh phlln - OJ + il -+ 2 (lbieu dien bien2 dt dt lCItthi€m thea thbi gian cua nang hlqng tit tru:dng tlch liiy.3 de- thanh phan - (f,AI - Vlidl - ~n vili c6ng suat CO bien doi thanh2 dtcong sua:t di~n trong may. Trang truong hqp tQa d¢ gall voi roto, khi do I.atoe d¢ We thbi, momen di$n tit bang:3Melt = 2 (!fllliq - !/qiul (3-28).Ket qua Day lll(Jt IBn nlia trung vai bieu th(ic (3-13) doi vai may dit;lnlll¢t chieu tcing quat.3.4.5 Khcii ni~m ve may dh~n t6ng quatBien d6i Park co the ap dng cho cae lo~i lllay di~n xoay chiflU bat kyoVi~c ch9D t~la d(J (Od, Oq) ph1,l thu9C vao cau true cua m;-iy va lo~i bai toaDthuong g~p.Vi dl vbi may di~n dong h¢ Dfm ch9D t9a d¢ gaD voi roto va dnh den dohdoi xung eua nilly_ D6i vai may di$n khOng dong bi) bien doi Park co the apdlng cho stato va roto. Sl,l d6j xling llH.lch ttl cho phep tuy y chr.m b~ t9a d¢.Bien doi Park cung dlh;1C ling dlng cho cac lo~i may di$n khac nhu maydi~n phan khang, may di~n xoay chieu co vanh gop...Nha bien deli Park quan h$ giG:a tit thOng va dong di$n dlt9c dan gianbOa va thl,lc te gi6ng nhu truang hap may di$n mi)t chieu tong quat.Bien d6i Park cho ta thay 16 sl,1 tuong tv cua qua trinh bien d6i nang lU9ngdi(ln cd cua cac lo~i lllay di$n quay khHc nhllu vi the ta gQi cac phuong trlnhPark IA phuong trinh may di~n tong quit. Cac phuong phip nghiAn cuu quatrinh qua di) cua cac lOJ;li may dien khac nhau co nhieu d~c diem chung. Tuynhien d6i voi tUng lo~i may dien khac nhau cling co nhftng npt rieng can luu y.3.5 MAy m¢N DONG BO3.5.1 L$lp phLJong trinh may di,n dlmg bet au dl,mg bien d6i ParkCho may di$n dong b¢ ba pha, hai cl,1c, sd do bi,§u di~n tren htnh 3.7 ta63
  64. 64. nh~n thay:- 1ren stato ha day quan pha a, h,c co cac t.rlc I~ch pha 2-1/3.- 1rEm rOto day quan kich tu kyhi$u bflng ehi s6 f:fr~lc Od eua M t9u d(J (Od, Oq)ch9n trung vai trl,lc tu euan kieh ttl.Khi quay vt t.ri Od dl1Qc dlo.lc trungbang gdco = (Oa, Od)of!otfren rota cd bo tri cae day qUllncan dju ngan nwch. Ta cd the bieu di€inbang hai day quan ngan mach Dthea trl,lc d9C Od va Q theo tr~lcngang Oq.Neu cac day qWln stato ut1:JCxem nhu may phat va day quankich ti1 xem nhl1 tAi cac phl1dngt.ri.nh di~n clla 6 day quail. Ii!:cllfu,,=-R),,-ot-Ri[dlJ.c ~ - -~dtdV1(3- 30), ~R[il +dt0 R)i[)dl.{i)~ +-~dt0 R()iOdrf()~ +--dt64bd I~ ~CHlnh 3.7. S(I db day quin th,Jeeua may di~n doog be.~dHlnh 3.B. SO db may di~n dOng b6theo true d va q.G
  65. 65. trong do Ra la di/i!n tro pha cua day quan phlin ung.RJ) va RQ di(!n tro day qua:n canRfla di~n tro dAy qu.fn kich tit.Sau khi ap d1,lng bien d6i Park cac phuong trinh (3-30) tucmg tL! nhu(3-25) duc;lC th~ vaa (3-26) va duc;lc bieu diil!n thea cac d:;ti IUc;lng d va q trenhlnh 3.B.Tren hlnh 3.8 cac quan M gifta tit tMng va dong di~n th~ hiliin tuong UlCtit gif:r:a cac cU9n day co tr1,lc tit 00 dinh vai nhau, m~t khac hai h9 vullng gOcnhau. Cac quan h¢ nay la tuyen dnh do gill thiet may khOng Mo hoa, cac h$so khllng ph1,l thu(lc fJ va duQC phan chia thanh hai M thOng d6i xung. MqtM thong cAp 3 ang voi cac dAy quan d,- f va D cua tr1,lc doc, m¢t M thongdip 2 ung voi cac day qua:n q va Q cua tryc ngang va thanh philn cu6i cungbi{iu thl quan h~ gifta V va ioD~ thu~n ti~n cho vi~c bieu dien cae d~i IUQng khac nhau ta thuong dungdon vj tuong doL Cac gia trj tuong doi du9c ky hi$u bang chu nha bang tyso cua d:;ti IU9ng thvc va d:;ti luong djnh muc cua no.Thea d~i lu{;mg tuong d6i ta co tM bieu di~n cae phuong trlnh cua maydi(n dong bo:Cac phuong trlnh di$nur ~rfif0 ~rr)DdJ/d_ dJ/qdtdl/dtd~r+--dtd~D+--dtCac phuong trlnh tit:(3-31)(3- 32)(3- 33)(3- 34)65
  66. 66. I 1/u I I nlaf IllaD i :. ~r~mal In mIDI ,I ilI , , .i 1/0 I lllal) mil) Inn ll) ,(3-35)11 Iq UlI). iq! .,I~i , ,. I! lUaO IUU lO!(3- 36)!f~ I i(3- 37)Cae phuong trinh nang IU!;lng:M ~w(I/uiq - I/Iid) (3- 38)2H dw,M, - M ~---w dt(3-39)trong do: lu lq la di~n cam gan voi cae di~n khAng d~ trung cho ch€ d¢ xacI~p dong b(l voi tan so w; H la hang 90 d¢ng nang.(3- 40)di~n khang tlong bi? ngang trlc xl] = lqw (3-41)diEm cam Iff IOD lIN Iii cae di~n cam cila cac day qulln f, D, Q va lllrnIii hCi cam gii1a day quan f va D.- hCi cam gii1a m¢t pha stato a, b, c va day quan r6to vi dl maf ia hei camgiua pha a va cu¢n kich ttl trl,1e ti€p tham gia vao bieu thdc cua suc di~nd¢ng trong.dl,~n dun 1 gan voi dil)!n khling thu tl,1 khong:x = low.3.5.2 VI dl,J (rng dl,mgH~ phuong trlnh (3- 31) den (3- 39) eho phep nghien euu d~e dnh cua maydi~n dong b(l (1 ch€ d(l bat kyo Khi toc d¢ coi lil khong doi M thOng Iii cacphtwng trinh tuyen dnh, co the giai ba.ng giai dch. Tuy nhien noi chung vitoe d(l thay dl1i can co cae b(:t dilu chlnh di~n ap va toc d(l cae phuong trinhtren khli phuc tl,lP, can dUQc xu If bang may dnh.66C che d) xlic Ji;l.p dong b¢ ta co:uq = -r}q + xuiu + e,e = In~fwif.(3 _42)(3-13)(3-44)
  67. 67. Ta nghi€m cuu cac thOng so d:;ic trt1ng cua may di~n dong b¢ 0 ch€ d( quade). 0 day ta gioi h~n toc d¢ la kMng d6i, bang toc d¢ dong bQ, nghta la chixet den qua d¢ di~n ttl, b6 qua qua d9 di~n co va khOng co tMnh phan thatv kMng. Ta co the ap dl:lDg bien doi Laplace cho cac bien thil!n cua cac d~i1t1Qng di~n. Cac phuong trlnh (3-31) dt;n (3-34) tro thanh:6.ull(p) = -ra6.iip) - P6.1fd(P) - w6.1jq(p)6.Uq(p) = -ra6.iq(p) - p6.1flj(p) + w6.1j,/p)6.ur(p) = rrAir(p) + p6.1fr(p)o = ro6.if)(p) + p6.1jf)(p)o = rQ 6.io(p) + p6.1jo(p).(3- 45)(3- 46)(3-47)(3- 48)Trong cac phuong trtnh (3- 35) va (3- 36) nen thay the 11 va i ba.ng cacsai phan 6. thea p.Khu 6.if 6.Vp 6.i[) va 6.Vn hung 5 phuong trlnh (3- 35), (3- 46) va (3- 47)Phuong trlnh eon IfP xulit hi¢n 6.1fd nhu ham tuyen Hnh cua 6.id va 6.uf.Cae M s6 lit. phan thuc bl)c 2 cua p (3-49)Ttl: va mA.u s6 cua Id(p) va g(p) cO cac nghi~m thl,tc vit. am co the bHludi~n duai d~ng:Xu (1 + TdP)( 1 + TdP)Id(P) =w (1 +.. Tdp)(1 +. TduP)ham truyfm kich ttl toan tu:mlf 1 + -TDPg(p) ~- -;-:--=-----::-:---;;;;;---:rf (1 + TdrJl)(l +. TunP)(3- 50)(351)Cac hllng s6 thai gian Tll va Tdo Ia hang so thOi gian qua d¢ cEi Is, vaIan han con ha.ng s6 thai gian Td Td vit. Tn lit. Mng s6 thai gian sillu quade) eo 0, Is vA nho hon,VI ch€ d¢ bien thien kha chc).m (tan s6 tuong dttong eo 1 Hz) do do di~nkha.ng qua de) dQC tr1,lc(3- 52)voi xd::::: O,lxu .Cae eh€ di? bien thiE!D nhanh co m$,t di~n khang sh~u qua d¢ dQC tr1,lC67
  68. 68. Xd ;0: XdTdTdt)voi Xd :::: 0,7xd,la khtl 6.i{) va 111fJQ giua ba phudng trinh (3-34) VB (3- 36)Phuong trlnh eon l~i co the dUQe vilit:6.Pq(p) = Iq(p)6.iq(p)lq(p) la phan thuc bf).c 1 cua q, co th~ viet duai d~ng:1 + T Px ~_=c-­Iq(p) ~-- ~OJ 1 + TloP(3- 53)(3-54)(3-55)Cac hang sci thdi gian sh~u qua dl) T l vi!. Tqo cung cB Td va Td,, taeo di~n khang si{!u qua d9 ngang tr1,1cT Ix ~ x --Ci TIvdi xI~ x d3.5.3 Nghiin cuu ngln m,ch ba phs khi khOng taiCae tinh toan lien quan den che dO qua d(l cua may di~n dbng bO thuCJngrat dai ngay ca trong truong hQp don gian nhat. Tuy nhien ta xet m()t trongcac truong hQP quan tr9ng trong th1Jc te vi cac Iy do sau dlly:- phuong phap nghien cllu eo tM stl dlng cho nhieu vi d1,1 khac,- che d9 nay thuong dUQc su dung trong thtl nghi~m, bhng cach ghi 81,1bien thien dong di~n theo thm gian Mi vi phan tlch bang bieu do dao d(lngcho pMp dnh toan cae th6ng s6 ehu yeo, No eho phep t~o nen qua trtnh xaed~nh bang th!Jc nghit:!m cac thong s6 eAn thiet cho vi~c nghien cuo toon b9qua trlnh qua d9,Ngan m~ch khbng tai bao gom lo~i bO mOt each d9t ngQt cac di~n ap uaull U- do do cac di~n ip ud va Oct con di/iln :ip kkh tu of van gill kh6ng d6i.Khi kh6ng tEti a eMf d9 x:ic I~p dong bt) ta co: ud = 0, u, = e,Ap d1,1ng vao cac phudng trinh (3-31) va (3-32) cac bien thien:LlUd(p) ~ 0e6.uq(p) ~pllur(p) ~ O.GEl
  69. 69. Thay th~ vao (3-49) va (3-54) vao (3-45) ta duQc:°== -era + pl,/p)]Lli,/p) - wlq(p)Lliq(p)e= wlip)Llitl(p) - ern + plq(p)]Lliq(p)PGiid h$ thong nay ta dllQC Lliip) va fliq(p).vi co cac d~i illQng tham gia vao phuong trinh cho pMp dan giAn hoaHnh toan m(lt cach dang k~. Dau tien djnh thl1c cua M thong co the· dUQCviet mOt cach gan dung:D = id(p)lq(p) (p2 + w2 + 2ap)vairn w w 1a = - ( - + - ) = - .2 x(j x q TnTala hang so thai gian cua stato co 0,1 den 0,2 , a wTa bi€t rang djnh thuc xulit hi~n trong mau s6 cua cac nghi~m 6.itl(p) vaLli,!(p) va nghj~m cua mAu thuc cho ta guy lul)t bien thien theo thai gian.Theo bi~u thuc (3-SO) va (3-55) dinh thl1c D duqc viet duai d;:tngD__ XdXq (1 + TdpHl + TdP)(l + T qp)(p2 + w2 + 2ap)w2 (1 + TdllP)(1 + Td,,p)(l + TqnP)Quan sat mau s6 ta thlIy c6 cac hang s6 thdi gian xuat hi(!n trbng bi~uthuc tuc thai cua Llid(p) va Lliq(p):- Thanh phAn tAt dan vaj hAng s6 thai gian Ttl, Td Tq- Thanh phan daD dqng vaj tan 86 w va M so suy giam a.Ti~n hanh dnh toan bang cach phlin chia thanh thila s6 huu ty va dangiAn hoa dnh toan theo dJ cae d~i lUQng1 1 1 1 1 1 1( - va -- ) ( - -- -- va - ) « wT T T T J T T Td do d do q go aVi ch€ dQ ban .dliu la k.h6ng t9i citc dong di~n ban dau va gia 136 fl oangdong di~n can tim, ta 00:1 1id(t) = -e[- + ( -X.l xde1- )exp(-tiT.l) +Xd+-- exp(-at)cos wtx.l1(--;-,X d1---; )exp(-t/Td)] +xd69
  70. 70. eiq(t) =~,-, exp(~at)sinwtx ITrang truang help nay b6 qua thanh phan TiTinh toan dong di~n 1ll9t pha bat ky, sa d~ng dl;li h19ng v~t If ta dt1Qc_ 1 1 1-EV2[~ + (-Xu Xd- - )exp(-t/Td)Xd1+ (XuEV2+--2EV2+--21I-X1( -Xd1+--- Jexp(-at)X1- lexp(-atlXIcost/cos (2wt + fl,,). (3-58)Cae dong di~n ih(tJ, ic(tl nh(m dt1Qc hAng each thay t.he tuong ung [{;I -(2;r/3)] va [w - (4JT/311Ket qua bieu do dong di~n qua d(l clt1Qc ve tren hinh :3. 9 + 3.11.D,§ nh~n thay r!ng t.rong iacong thtic (3-5Bl thanh phancuoi cung (thea coszwt) co biend¢ rat nha so voj cae thanh philnkhac do do co the b6 qua va caehang so thoi gian Td va Tu nitkhac nhau.Trang bieu thuc (3- 58) dongdi~n ngan mach co 3 thanh phan:- Thanh philn dau tiEm trongJau ngo~c vuong lit thanh ph~i.ntat dan chu ky 1.lng voi 51! ng-ancan tu thong ban dau trong nu).chrota. Hang so thbi gian Td chuyeu dll!;lC xac dlnh Mng cac thongs6 cua lll:ch kich tit va Td theathong so cua cu¢n can d;c tr1,lc,con tu thong tlldng ling vai70, tA.----WWTvMtHlnh 3.10. Ooog ngAn mlch pha B........ . .NWffivmm tHlnh 3.11. DOng ngar. miilch pha C.

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