Điều khiển động cơ DC sử dụng bộ băm xung áp ( bộ chopper

Tap Chl GTVT KHOA HQC - CONG NGHE 6/2011 DIEU KHIEN DONG COf DC SlT DUNG DO D A M XUNG AP (DO CHOPPER) TS DONG VAN H U N G TrQdng Dai hpc Giao thong van tai TP Ho Chf Minh Tom tat: Nang eao chat lugng dieu khiin cae dd'i tugng la van de quan trgng thuc ti' khai thac cae thiit bi Bai bao trinh bay phuong phap nang eao chat lugng dieu khien ddng co dien DC sd dyng bd bam xung diin ap - bg chopper Abstract: Improve quality control objects are Important issues In the actual mining equipment This article presents methods of improving the quality of DC motor control using the hash pulse - the chopper Mddau De dieu chinh tdc dd ddng eo dien mdt chieu chung ta cd the sQ dyng phUdng phap thay ddi dien trd phan Ung, phUPng phap thay ddi tQ thdng hoac phuong phap thay ddi dien ap phan Ung PhUPng phap dieu chinh tdc dp ddng cd dien DC bing dien trd phan Qng lam cho dac tinh cd cua ddng CP mem, tai thay ddi dp syt tdc Idn, gay tdn hao ldn, hieu suat thap, hien hau nhU khdng dupe sQ dung PhUPng phap dieu chlnh td'c dp ddng cP dien DC bang each dieu chinh tU thdng ddng eP cd nhupc die'm la dai dieu ehinh hep va sai sd dieu chinh Idn, thudng dupc ap dung cho trUdng hpp can td'c dp lam viee Idn hPn tdc dd djnh mUe PhUdng phap thay ddi dien ap phan Ung de dieu khien tde dp ddng cd DC hien dupe sQ dung nhieu vl cd hieu suat cao, dai dieu ehinh rdng, dac ti'nh cd tdt Cd nhieu phUOng phap dieu khie'n dien ap phan Ung, bai vie't chung ta sQ dyng bd bam dien ap DC; Dien ap dupe dieu khie'n bang each thay ddi dp rdng xung nen dupc gpi la phUPng phap dieu bien dp rdng xung (PWM_Pulse Width Modulation) Trong phuong phap nay, be rdng xung T^n thay ddi, toan bd thdi gian chu ky T dupc giO cd djnh NghTa la tan sd ddng md SW (tan sd bam) la khdng ddi Cau true cua he thong Cau true cua he thdng dupc md ta tren hinh bao gdm cac khdi sau: - Bd dieu khie'n DAF bao gdm may tinh va vi dieu khie'n ddng vai trd thuc hien eae giai thuat dieu khie'n Giao tiep giQa vi dieu khie'n va may tinh thdng qua cdng LPT hoac cdng COM Bp Mu khin MAY TINH * Toe dp mong muon Do: twp^g diiu khiin Vi di^u khien D$ng cv DC ; Thiet bi cdm bien Encoder - Ddi tupng dieu khie'n bao gdm bd dieu bien dd rdng xung PWM va ddng cP dien mdt chieu ghep ndi tiep Tin hieu vao la dd rdng xung va tin hieu la tdc dd ddng cP - Thiet bj ludng cam bien sQ dyng encoder de xae djnh tde dp ddng cP Tde dd ddng cd dupe tinh bang dao ham cua sd xung encoder theo thdi gian - Ngoai cdn cd cac thiet bj hien thj, thie't bj nhap dO lieu de dieu khien he thdng va cac den chi bao Mo hinh toan hpc cua doi tQpng dieu khie'n Ddi tupng dieu khie'n bao gdm cP eau chap hanh la bd bam dien ap DC va ddng cP dien mdt chieu kich tU ddc lap ghep ndi tiep PWM Bp dieu bien rong xung D o n g CO' Bo lpc L-C lc.(t) DC Hinh Sc khdi cua ddi tugng dieu khien Phuong trinh toan cua ddng eo mdt chieu He phuong trinh toan hpc md ta qua trinh hoat ddng eua ddng co dien mdt chieu bao gdm cac phuong trinh sau: Phuong trinh can bang dien ap phan Qng: ^appiO = RJaif) + L, dt + ^e.f(0 (1) \PhUPng trinh can bang dien ap phan cam: di_^ (t) uAt) = RAAt)^L dt (2) PhUPng trinh can bang mdmen J dco{t) T{t)-Z^{t)-K^CO{t) (3) dt Trong dd: - Vgpp: dien ap phan Qng ddng cd, V - V,emf (t): sQc dien ddng ddng eP, V - ia(t): ddng dien phan Qng, A - Rg, Rf: dien trd phan Qng va phan cam - Ly: dien cam phan Qng va phan cam H - T(t): md men dien tQ, Nm - Tp(t): md men tai, Nm - Kf: he sd ma sat tren tryc ddng ed, Nms - J: md men quan tfnh quy ddi ve tryc ddng ed, kg/m SQe dien ddng Vgmf(t) va md men dien tU T(t) dupe xac dinh theo: (4) Hinh So dd eiu trdc cua bo diiu khiin m=Kj{t) (5) m KHOA HOC - CONG NGHE Trong dd he sd tQ thdng Kb va he sd md men Kp tinh tQ bleu thQc: (6) PhUOng trinh trang thai: i,(0" J r^,(oi J ^2(0 LjAt)0}{t) (8) (9) Laf: hd cam giOa phan cam va phan Qng ddng cd, H TU cac phuong trinh (1) - (9) rut he phUdng trinh toan hpc md ta ddng cO dien DC: ,(0 ait) dt La (10) K, droit) K„ ^r,it) -mit) Ki.t) dt J "'" J Md hinh md phdng tuyen tinh hda cua dgng co difn mgt chieu TU phUdng trinh (10) sQ dung Toolbook Matlab simulink chung ta lap dupc sd dd md phdng ddng CO DC -KD - - • W ; » j -l-J^;>^-^v »|^^;;» QD->" lf>t«()r*tor1 Ojim | l - 0jjn7 lnt«gr«toi2 spttd G3Hinh So dd md phdng dgng eO di$n DC Ddi vdi ddng cd mdt chieu kich tU ddc lap va song song thi coi nhu tU thdng khdng thay ddi (Cac thdng sd Kb va Km phUPng trinh vi phan md \k toan hpc ddng eO mdt chieu khdng thay ddi), ed the coi ddng cO dien DC la ddi tupng tuye'n tinh bac hai TU he phupng trinh (10) xay dyng dUde ham truyen eua ddi tupng dieu khie'n (ty sd giOa td'c dp va dien ap), va sau bie'n ddi dUOc phUOng trinh: Gis) = -''^'^ - w K LJS'+{L^K^ + RJ)S + (12) J W R^K^+K^K, 0 ^ (13) 3^2(0 ^2(0 PhUdng trinh md ta ddi tuong cd the viet lai nhii sau: {xit) = Ax{t) +Bu{t) \yit) = Cxit) +Du{t) (14) Trong dd: (0(t) a)(t) xit) y(t) '•(OJ Tit) K, J R K, -0