Str DUNG DSC dsPIC30F4011 TfflET KE BIEN TAN BA PHA THEO NGUYEN LY DIEU CHE VECTOR KHONG GIAN - SVPWM
TS. Qudch Diicc Cudt^, SV. Ngd Kim Anh^
'Dgi hgc Nha Trang
^Dgi hgc Bdch Khoa Hd Ngi
Tom tdt: Ngdy nay cdc he truyin dgng dien xoay chiiu ba pha thudng sic dung biin tdn de diiu khiin dgng ca. Vdn di kho khdn khi thiit ki bien ldn la phdi tgo ra dgng sdng hinh siij vdi song hdi nhd nhat Trong bdi bdo nay chiing toi gidi thieu sic dung vi diiu khiin so de thiet ki bien tdn ba pha theo nguyen ly diiu chi vector khong gian. Thudt todn diiu chi biin tdn se dugc kiem chiing tren mo hinh phdn Cling su dmg kit diiu khiin DSC 16-bil (dsPIC30F4011 Digital Signal Controller) cua hang
Microchip.
Abstract: Nowaday controlling devices in modem three-phase motor control system using inverter is popular. One ofimportannt problems is how to generate sinusoidal waveforms with minimal harmonic. In this paper, we develop an algorithm for three-phase inverter modulation using space vector modulation method. The algorithm is tested on 16-bit DSC hi (dsPIC30F40I I Digital Signal Controller) of Microchip company.
Keywords: Space vector modulation, three-phase inverter, dsPlC
1. Gidi thieu
Thi8t bi bien tan ba pha hien nay thudng sir dyng phuang phap di6u ehe vector khdng gian SVPWM. Uu diem eiia phuang phap la ed the tgo ra di6n ap hinh sin vdi sdng hai nhd. Ngoai chirc nang dilu chmh tin sd cd dp min cao phuang phap nay edn cho phep tryc tiep dieu chinh bien dp dien dp ba pha dau ra ciia bien tan mdt each d l dang.
Vdi sy phat trien cua ly thuyit SVPWM va edng nghe chl tgo linh kien dien tu cdng suit da dua cdng nghe chl tgo biln tan budc sang mpt giai dogn mdi - giai doan ciia biln tin SVPWM. Ngay nay, chiing ta cd thi de dang bit gap biln tan SVPWM trong eac thilt bi cdng nghiep eiia SIEMENS, OMRON, MITSUBISHI... Cae biln tin cdng nghi?p nay ed chit lupng va dp tin cay rit cao, ngoai ra chiing cdn dupc tieh hgp cac chirc nSng dilu khiln DTC, FOC va cae ehuan giao tilp truyen thdng cdng nghiep...
cho phep tgo ra mdt he thdng truyin ddng di?n cd miic dp ty ddng hda va chit lupng eao. Tren thye t l vin tdn tai nhiing he dilu khien truyen dpng dien khdng su dyng hit cae chiic nang eiia mdt biln tin edng nghiep.
Do do vi?c yang bi biln tin cdng nghiep cho cac h? truyin ddng kieu nay y d len lang phi va khdng can thiet.
Trong bai bao nay chung tdi se gidi thieu ket qud budc dau eua viSc nghien ciiu ehe tgo bien tan ba pha SVPWM gia re ed the ling dyng trong cac he truyen dpng di$n xoay chieu ba pha khdng yeu eau cao ve ehat lupng dieu khien.
2. Nguyen ly dieu che vector dien ap cho biln t i n SVPWM
Hmh 1. Sa do dgng life cua bien Idn SVPWM So dd mgch ddng lyc cua biln tan ba pha nhu ygn Hinh 1. Gpi VAN, VBN va VCN la tin hi?u d i | n ap pha, VAB, VBC, VCA la dien ap day cua bien tin. Tir Qi din Q^ la sau van cdng suat, cac van nay duge dieu khien bdi eac tin hi?u a, a', b, b', c va c'. Khi mdt van thudc nhanh tren md {a, b hoac c ed miie logic la I) thi cac van phia dudi ciing nhanh vdi nd s€ khda {a', b' hoac c' se cd miic logic la 0). Qh tgo ra dien ap VAN, VBN va VCN hinh
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sin ngudi ta se dieu chinh ddng md cac van theo mdt chu trinh xae dinh. Mdi quan he giiia vector logic dieu khiln [a b ef va dien ap dau ra cho bdi phuang trinh (1).
2 -1 -1
-1 2 -1
-1"
-1 2
a b c
(1)
Tronp dd V^c la ngudn ap mdt chieu cap cho bien tan. Tu phuong trinh (1) ta cd thi tao ra 8 trgng thai dilu khiln logic tuong ling se cd 8 vector dien ap ehuan Vo, Vj,..., Vj.
Cac vector dien ap ehuan cd dg ldn IVjJi, lech nhau 60**, ehiing phan chia khdng gian dieu che thanh 6 viing (Sector I, II,..., VI) nhu yen Hinh 2 va dupc dung dl dilu ehi dien ap xoay chieu ba pha.
cin chii y ring vector dien ap Vo va V?
tuong ling vdi cac trudng hpp toan bp 3 van tren Q1Q3Q5 hoge 3 van dudi Q2Q4Q6 cua biln tin khda hoan toan, nen \Vo\ = [K?! = 0 trimg vdi gdc tpa dp. Qua trinh dilu che vector Fj tir 6 vector ehuan Vi, K2,..., Ve nhu sau. Gia sir vector Vs nim d gdc phin sau dau tien (Sector I), dl thye hien V^ trong thdi gian T, ta cd thi thye hien V; frong thdi gian Ta va thye hien Vj frong thdi gian 7/,, [I], [3], [4].
(OOt) (101) Hmh 2. Khong gian dieu che vector dien dp V,
Ba vector di$n ap hinh sin lech nhau mpt gde 2^-3 se tgo ra mdt vector dien ap Vg quay vdi tde dp co. De thue hien thuat toan SVPWM ta dua vao h^ true tpa dp cd dinh a- P (Hinh 2), tryc a trimg vdi tryc pha A [!]
[2]. Quan h | chuyen ddi dien ap ba pha sang h0 tryc tpa dp cd dinh a-jff cho bdi (2).
VA afl -1/2 -1/2 "• ^'
^J"3[o >/3/2 -^ll_
Vs dugc xae dinh theo (3) va (4)
\V\ = abs ^jvfi^
--0}t = 27rft = tm-'\ --f-I (4)
Hinh 3. Dieu chi vector V, trong Sector I
^V^dt= ]v,dt+ J V2dt+ j V^dt (5) TV=TV+TV,+TV^ (6) Ydi T= Ta+ Tb+ To, frong dd To la khoang thdi gian ngung din cac van, tuang ling vdi vectordi^n ap I^o(OOO) hogc Vyill 1).
Do Vo va V7 cd bien dp bang khdng cho nen
Tir Hinh 3 va phuang trinh (7) ta co
(2)
|K,|sin «i = | | F , | s i n [ | ]
K | s i n ( | - ^ ) = | | f ^ | s i n ( | ) Thay Vi=V2 = 2VJ3 vao (8) va (9)
(8)
(9)
T, =T •—!^sin d
(3)
r__,m
sm Ip (10)(11) Cong thiic tdng quat tinh r„, Tj cho tit ca cac Sector trong mi8n di^u ch8
7 ; = 7 - ^ s m l ^ - — ; r l (12)
(13)
(n^I)T
PWM interrupt PWM interrupt Hmh 4. Gidn di PWM trong Sector 1
Trong dd A = 1, 2,..., 6 tuong iing vdi cac vung Sector I, II,..., VI. Thdng thudng sdng mang de dieu che Vs cd dang doi xung nhu Hinh 4. Can eii vao vi fri viing dieu che, thii ty cac vector dieu che va dien ap trong tiing vimg, lgp dupc bang diln ta thdi gian dong cit cua cae van cdng suat (Bang 1).
Bang i: Th&i gian dong cat tren cdc vung
• Budc 3: Dua fren gia tri ^ xac dinh vi tri vector Vs. Tir dd lya chpn van ddng md theo chu trinh phan bd thdi gian fren Bang 1
3. Kit qua thirc nghidm 3.1. Mo hinh phan cirng
Md hinh thye nghiem sii dyng DSC dsPIC30F401I, day la bd dilu khiln sd (Digital Signal ConfroUer) 16-bit cua hang Microchip. Tren dsPIC30F4011 tieh hpp 48 Kbytes Flash ROM chuang frinh, 2 Kbytes RAM va 1 Kbytes EEPROM dii lieu, tdc dp tinh toan len tdi 30 MIPS [5]. Ngoai ra tren DSC eung tieh hpp sin eae module ehiie nang danh cho dilu khien va giao tiep nhu:
PWM, QEI, ADC, TIMER, UART, CAN, I2C, SPI...[5]. Trong qua trinh thi nghi?m, DSC dupc cai dat hogt ddng vdi tdc dp 20 MIPS va dien ap ngudn nudi 5 VDC.
Sector I
II
III
IV
V
VI
Cym v a n p / p j p j Qi=Ta+Tb+T[/2 Qj=Tb+Ti/2 Q5-T0/2 Qi=T.+T«/2 Qj-T.+Tb+To/2 0 5 = T , ^ Qi=T,,Q Qj-T.+Tb+T,/2 Qi=T,+To/2 0,=T«'2 Q,-T.+T,/2 Q!-T.+Tb+T,/2 Qi=Tb+T,/2 03=T,C Q5=T.+Tb+Ti,/2 Oi-T.+Tb+T„/2 03=T,/2 Qs=T.+T„/2
Cvm ymQiQM6 Q 4 - V 2 Q1-T.+T0/2 Qj=T.+Tb+T„/2 Q4=Tb+T,/2 Q.-T,/2 Q2-T.+Tb+To/2 Q4=T.+Tb+T„/2 Q6=T,/2 Q2=T.+T,/2 Q4-T.+Tb+V2 Q6=Tb+T,/2 Q==T</2 Q4-T.+T»/2 Ql-T.+Tb+Ti/2 Q2-T0/2 Q.=T„/2 Qb-T.+Tb+T„/2 Q2-Tb+T,/2
Cae bude dieu che vector PWM Budc 1: Can cii vao yeu cau ciia dien ap ba pha VAN, VBN va VQN tinh Va, Vp, Vg cimg gde quay ^
Bude 2: Tii gde quay ^ xae dinh vi fri vector Vs dang thudc vimg dilu chl nao. Tinh Ta, Tb theo (12) va (13)
Hinh 5. Mo hinh thuc nghidm
PWM module bao gdm 3 kenh 6 dudng de dieu khien 6 van cdng suat cua bien tan.
Tan sd sdng mang len tdi hang chyc kHz, hinh dang cua sdng mang cd the cai dgt d dang ddi xiing hoae phi ddi xiing [5]. Dp phan giai len tdi 16-bit. Cho phep lap trinh thdi gian ngung dan khi chuyen ddi trang thai logic fren mdt nhanh van. Trong qua trinh thye nghiem, lupng thdi gian ngung din dugc cai dat la l|is.
Tren Hinh 5 la md hinh cua bien tin 3 pha vdi sau van MOSFET. Diu vao dilu ehinh cd the lya chgn la tin hieu analog tir bien frd hoae ban phim. Ngoai ra tan sd dgt va bien do dien ap cua biln tin ciing dugc lya ehgn thdng qua tin hieu nhan duge tu cdng UART.
Tde dp eai dgt cho cdng UART la
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19200 baud. Mach dieu khi6n va mach dpng lire duoc each ly vai nhau qua bo phan each ly quang toe dp cao TLP250. Bien dp xung diiu khiSn MOSFET ±15V.
Trong sa do thuc nghiem Hinh 5, mach dpng luc dupc thiit ki bai 6 MOSFET IRF540, cac phSn tOt MOSFET dupc bao ve qua dong, qua ap, xung dien ap va xung dong dien. Ngu6n cip cho biln tinKj^ = 12 VDC.
.'^.2- Ket qua thi nghiem
Hinh 6: Bien ap pha img vol tin so diSu biia 100 Hz, tto s6 song mang 3 kHz, tai dien tra.
Truong hop 6.a la gian dd diSn ap khong su dung bp Ipc va 6.b co su dung bp Ipc L-C (dien cam L = 100 jiH va tu dien C = 1 ^F). Tin hieu dien ap ra cila biln tin djng chtun xung voi dp rpng dupc dieu bien ty le voi bien dp dien ap hinh sin. Khi su dyng bp Ipc L-C cho thiy song hai da giam dang ke.
\/\/\/\/\}
•fl ••S6<irw>^'~tm' n"^' " ' M 2.5B[n5 CHI j ^ iT •innrr.v rft:' "innmw M s.nnr
6.a 6.b Hmh 6. Gidn do dien dp khi sU dung vd khong sir dung bo Igc L-C
^CKyT^y?^
J >^
7.bHmh 7. True Hep diiu chinh bien do dien dp ciia biin tan
Hmh 8. Diiu chd song sin a 25 Hz vd
Hinh 7: Dien ap day Omg vdi tin sd dilu biln 50 Hz, tin sd sdng mang 20 kHz, tai dien frd, cd sii dung bd Ipe L-C. Dieu chinh tryc tilp bien dp dien ap bien tan bang each thay ddi dp Idn eiia vector Vs thdng qua do thay ddi lupng thdi gian Tg va Tf, frong (12) va (13). Vi dy khi ^iam bien dp dien ap diu ra ciia biln tin thi can giam V^, dieu nay ddng nghia vdi giam Ta, Tb va khi dd To tang
500 Hz khi lan so song mang la lOKHz
len din tdi thdi gian ngung dan ciia van keo dai, bien dp dien ap trung binh frong mpt chu ky se giam xudng. De tm hieu dien ap cd dgng sin thi Vs < Q.SVdc [1], [2], hiy nhien neu Vs qua nhd thi khi do sdng hai bac cao Igi ldn va anh hudng xau tdi dien ap diu ra.
Hinh 8: Tan sd eiia bien tin cd thi dilu chinh tdt trong dai tin sd thip va tin so cao din 500 Hz.
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4. Ket luan
Biln tin SVPWM cd chit Iuang sdng hai nhd nlu tin s6 sdng mang cao va bd Ipc L-C cd cong suit dii \6n. Nguyen ly SVPWM khdng chi eho phep dilu chmh tin sd ma cdn true tilp dilu khien bien dp dien ap dau ra cua biln tin thdng qua viec dgt gia fri Vs. Tuy nhien dl dam bao sdng hai frong pham vi eho phep thi miie dp dilu chinh bien do dien ap nay eung phai nam trong gidi ban nhat dinh.
Bai bao chi phan tich va thue hien giai thuat SVPWM fren kit dsPIC30F4Qll, mdt sd chirc nang day du cua mdt bien tan hoan chinh nhu dp an toan, dp tin eay, tinh tuang thich vdi he thing cdng nghiep... chua duge de cgp den. Nhiing van de nay se dupc chiing tdi trinh bay trong nhiing npi dung nghien ciiu tiep theo.
Tai li^u tham khao:
[1] Nguyen Phiing Quang, "Truyen dpng dien thong minh," Nha xuat ban Khoa hgc va Ky thugt. Ha N p i , pp. 1-43, 2006 [2] Duc-Cuong Quach, Quan Ym, Yu-Feng
Shi and Chun-Jie Zhou, "Design and Implementation of Three-phase SVPWM hiverter with 16-bit dsPIC," IEEE 12th International Conference on Control- Automation-Robotics and Vision, Guangzhou, China, pp. 1181 -1186, 2012 [3] Dorin O. Neaesu, "Space Vector
Modulation - An Infrodueton," The 27th Annual Conference of the IEEE Industrial Electronics Society, pp.1583-1592, 2001 [4] K. V. Kumar, P.A. Michael, J.P. John.
"Simulation and Comparision of SPWM and SVPWM Confrol for Three phase Inverter," ARPN Journal of Enginneering and Applied Sciences, Vol.5, No.7, 2010 [5] Microchip, "dsPIC30F40n/4012 Data
sheet, High Performenee Digital Signal ConfroUer".
Ngiy nhan hkv, 15/12/2013 Ngdy chip nhSn dang: 31/12/2013 Phan Bi^n: TS. Dang Xuan Kien
DONG COTHirc HIEN....
Tiep theo trang 79
TRONG
radi 1: Ma hbih chien liMc dmjfn jii ( i ^ i i ^ Chtog-Wm Lin (2010)
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gid trong cdc cong ty da quoc gia d Vi$t Nam, luan van thgc sT
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18-21 ; , Chin-Wen Lm, Hsiao-Chen Chang [
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3, pp. 278-292
Ngay nh^n bai: 15/12/2013 Ngdy chap nhan ddng: 31/12/2013 Phan bifn: TS. Liru thanh Tam
PGS. TS. Phan Dinh Nguyen
