Duong Quflc Tuin vd Dig Tap chf KHOA HOC & CONG NGHE 176(16): 8 9 - 9 5
THIET KE mtV KHifeN fiONG CO DONG BO TlT THONG DOC TRyC KICK Ttr NAM CHAM VINH CUtI LAM VIEC Vdl TOC Dp TREN DINH MlTC
Duong Qu6c T u i n ' , Nguyen N h u Hiln, T r i n XuSn Minh Trudng Dgi hgc Ky thudt Cong nghiep — DH Thdi Nguyen
TOM
TATDflng CO dong bfl tir thong dgc tme, kich tij nam chdm vinh ciiu (DC AFPM) khi su dung cdc 6 da tir thay the cac vong bi co khi a hai diu tryc, co thi cho phep dflng co lam vi?c vdi tflc do quay ciia tryc Idn hon tflc do dinh miic rat nhilu, Trong thyc t l c6 rit nhilu iing dung yeu cdu tflc dfl rit cao, tuy nhiSn chua c6 nhilu cflng tthih nghien ciiu ve vin dl nay. Mflt ttong cac bi$n phdp d l tdng tflc dfl dong CD ISn tten toe do dinh miic Id gidm tii thong cue cua rotor ( ! ^ ) . Bdi bdo nay dl xuit mgt giai phap nhdm tang toe do cua dong co AFPM Ifin tten t i c dfl dmh miic bdng cdch bom vao true d mflt dong di?n isd ngugc chilu vdi tir thong cue fp trong khi van ddm bdo toi uu v l mfl men ciia dflng CO. Kflt qud mfl phong chiing to tinh dimg ddn ciia gidi phdp dd dl xuit.
Tii- khoa: Ddng ca dong bd tir Ihdng dgc trtfc kich lit nam chdm vTnh cuu; AFPM. dieu khiin iSi uu; tren tdc do ca bdn; gidm td- thong
Chu- viet tit
AFPM axial flux permanent magnet NCVC Nam chdm vinh ciru DC Dgng co CAU T R U C D O N G CO C a u t a o
v l mat cau tao, D C A F P M cd nhihig net dac bi?t rieng, cu the modul stator cd the bao gom cac loai: Modul don chi cd mpt bp day q u i n va modul kep cd hai bfi day q u i n chung mflt loi va quay lung vao nhau. Rotor cung t u a n g tu, modul rotor d a n chi mpt mat cd nam cham vTnh ciru vd modul kep thi ca hai mat deu cd nam cham vTnh ciiu tua lung vao nhau, O day chpn ddi t u g n g nghien ciiu la loai cd hai modul stator don ben ngoai va mgt modul rotor kep ben trong n h u tren Htnh 1.
Hinh 1. Mdt cdt DC AFPM cd tich hap 6 d&lu hai ddu true (I. True; 2, 3. Staler va ddy qudn cua
DC phia phdi vd phia trdi, 4 Rotor nam chdm vinh citu; 5,6: Rotor d da tir ben trdi va bin phdi;
7,8: Stator vd ddy qudn cua d dd lie ben trdi vd ben phdi, zo, go-' Khe hd danh djnh giita rotor vd
stator cua DC vd d id)
' Tel: 0912 269147. Email duongquociuan-ldh@lnul edu vn
N g u y e n ly lam viec
Khi dien ap ba pha dugc cap eho cac cudn day stator, sinh ra cac ddng dien (ttong dd cd thanh phan /;,) chay trong nd, se t u a n g tac vdi tir trudng ciia rotor de t§o ra cac mfi men quay (M) va ddng dien trong cac day quan pha (thanh phan idi cua stator sinh ra cac luc d i y k^o (F) dua tren nguyin ly cua nam cham dien. N h d cd cau tao d^c biet va nguyen ly lam viec n h u tren ma rotor ciia D C se khdng cd dich chuyen dpc true mac du hai d i u tryc DC la hai fi dd tir. Dieu dd, cho phep khdng can dung them thiet bj chan e h u y i n dgng dpc true cua rotor va vi vay c i u tnic D C trd nen nhd gpn hon. Do each cufin day ma tur trudng quay sinh ra momen quay Mi va M2 trSn true rotor ciing chieu va tao ra luc day keo F, va F2 giira rotor va stator n g u g c chieu. Mfi men quay tdng ( M = Mj + M2) la tfing cua cac mfi men quay va luc day keo doc true {F = F/ - F2) la hieu so cua hai luc hiit.
Tii cau tao va nguyen ly lam viec co the coi day la hai D C A F P M chung rotor hay hai DC noi cung true vdi nhau.
M O HINH T O A N H O C C U A D C A F P M D u a vao cac tai lieu [ 1 ] , [2], [3], mfl hlnh toan ciia D C A F P M d u g c xay dung trong he tpa dp dq dupe t h i hien n h u (1), (2), (3), (4), (5).
Trong dd, chi so 1 t u o n g u n g vdi D C ben trai va chi so hai luong d n g vdi D C ben phai.
Duong Quflc Tuin vd Dtg Tap chi KHOA HQC & CONG NGHE 1 /oi,ioj: fiy-yj
'KL,+I:,
dl
-".i,.,i.
t,l'l»i".,2 = ^ ' . , 2 + 4 , 2 — r - + ' ^ , 4 , / 2 ' j a +I^.V',
""MI =2^, (ift,i,„+4,,;,, (i^l - A„ )]
' " « . = 2 2 , K i ; , ! + ' ; j j ' „ 2 ( i . i 2 - 4 , 2 ) l
" Z , *
^ i : = * , f e , , - l „ ) + * , 0 v - ^ J ^ - t 2 '
Tren /:finA 2 la cau true ciia DC AFPM theo mo hinh toan hgc a tren
(1)
(2) (3) (4) (5)
Hinh 2. Sa do cdu true cua DC AFPM VECTOR K H O N G GIAN DIEN AP, D O N G DIEN V A TU" THONG CUA DC A F P M TRONG HAI V U N G L A M VIEC Dfl thi vector khfing gian dien dp, ddng dien va tCr thfing ciia D C A F P M trong hai viing lam viec n h u tren Hinh 2 [ I , 5, 7]. Tir (2) va (3) thay ring, momen quay cua D C AFPM bao gdm hai thanh p h i n : thanh phan chinh vdi tich ippi^g va dianh p h i n phan khang do su 90
chenh lech dien cam stator ( i , ^ - ij^) :^ 0) gSy ra. Trong mpi che dp van hanh, D C AFPM phai san sinh mpt thanh p h i n momen phu dk bii thanh p h i n phan khdng. Thanh phin phan khang tfln tai mgt each rd rang nhung thucmg bi bd qua khflng tinh den trong cac phuang in dieu khien kinh dien. Viec bfl qua do giup lan dan gian hda he thfing d i l u chinh va tren thirc te cd the chap nh^n dugc trong dai tfic do quay dudi dinh miic, biri irong ddi do ludn co ha = 0 (Hinh 3a). Ngu-g-c lai, a dai tflc do quay tren djnh mirc, de tang tflc dp len ta phai giam tir thfing, luc dd phai bom mfit dong am vao tryc d. D C A F P M luc nay dugc van hanh d che dp giam tii thfing va ddng se co bien do Idn tang ti le thuan vdi toe dp quay rotor {Hinh 3b). Dieu d o dan den thanh phin momen phdn khang cd kha ndng dat duoc bien do dang ke khfing the bfi qua.
Khi dieu tflc cao han tan sfl c o ban, tin so co the tang Idn h a n / ; j „ „ nhung dien dp t/; khong the tang qua dien dp dinh miic t/^,,, toi da la chi giu' dupe Ul = Ua,„. Tir cfing thiic tinh siic dien dfing ciia D C cd the t h i y , dilu do se lam cho tir thfing se giam xufing theo ty ie nghjch vdi tan sfl, t u a n g duong vdi tnrcmg hgp D C mot c h i l u dieu chinh giam tii thfing de tang tflc.
-jX.i, JR.!,,
jRiiid - jXji
••.„/^l... ' \ b) -• ' Hinh 3. Vector khdng gian dien dp, ddng dien va lit thdng ciia DC AFPM Irong hai vitng ldm vi^c:
a) Duai tdc do djnh mdc, b) Tren tdc dd dinh mic Khac vdi DC dong bg N C V C gdn chim ben trong rotor va D C dfing bp t u trd, D C AFPM d viing tfic d o dinh muc trd xufing lufin duy tri dong iyj ^ 0. Vi vay ta chi xet vimg tren toe dp djnh miic.
TINH C A C GlA TRI T 6 I H A N VE DlgK AP V A D O N G DIEN
Duong Quoc Tuin vd Dtg Tap chi KHOA HQC & C 6 N G NGHE 176(16): 8 9 - 9 5 Trudc khi gidi thieu eac chien luge dieu khiln
khac nhau, chiing ta can xet den cac gidi h^n ciia dong dign v a dien dp [4, 5]. Gidi hgn cua v ^ c t a ddng dien:
• V-.. •- - (6) D u d n g gidi han ddng dien (6) la vong tron cd
ban kinh ij„, trong mat phdng (i^d, isq).
Gidi han cua v e c t a dien ap: Tii cfing thiic dien ap d che dp x i c lap khi bd qua dien trd stator u^ --<»,EJ^; u^ =OI^EJ^+Q}^IJ/^
Gia tt| dien ap pha c a ban cue dai ciia stator duoc xac djnh bdi dien ap mpt chieu trung gian:
Trong do: u^n, la gia tri dien ap mpt chieu I6n nhat dat vao bp nghich imi.
= CV../+I''-'.'+!',-''
(9)
Cfing thiic (9) la quy tich gidi ban difin dp la dudng elip trong mat phdng i^d - isq- Tren hlnh Hinh 4 minh hpa cac dac ti'nh gidi ban dugc xac dinh theo (6) va (9).
N h u vay, khi tang toe dp D C len tten tdc do dinh mire thi ciing vdi sy tang tan sd, tir thfing theo true d cua D C se giam, nhung n l u cluy tri
<()~6(fXz se cd gia tri mfi men la Idn nhat.
0
Giai lu/n di^n dp
/
Gioi hijn dong
1
Hlnh 4. Minh hga cdc dgi luang gidi hgn vd diem ldm viec tdi uu md men ciia DC AFPM o Iren Idc
dd dinh miic
Tir cong thiic tinh dien ap n h u (7) va (8), khi xet d c h l dp xac lap va bo qua dien trd stator ta tinh d u g c i^d, isq, gP' <P la gdc lech pha giua vector dien ap stator u^ va true q, tat ca thay vao cdng thiic tinh mfi men (2),(3),(4) ta cd:
Hinh 5. Md men DC AFPM vdi dien dp mot chieu Idn nhdt U =400V; tdn so dudng thdp nhdt Id lOOHz, 90HZ. 70Hz vd 50Hz. cite tri dip = 60".
Thay thfing so ciia D C A F P M vao (10), ta cd d^c tinh mfl men n h u tren hinh Hinh 5. N h u v^y, khi tang toe dp D C len tren tfic do dinh miic Ihl ciing vdi su tang tan sd, tir thfing theo tryc d ciia D C se giam, nhimg neu duy tri tp ~ 60° ta se co gia tri mfi men la Idn nhat.
THIET KE DIEU K H I E N D C A F P M C a u triic dieu khien tdng q u a t Ve mat c i u tnic thi logi D C A F P M khac h i n vdi cdc D C dien thdng dun^ hien nay, trong e i u tnic dieu khien se bao gfim hai vdng rieng biet la vdng dieu khien vj tri rotor dpc tryc (luc day keo) va vdng dieu khien tfic dp quay (mfl men quay) cho D C Cau true dieu khien tdng quat eho D C A F P M dugc minh hga n h u tren h i n h / f i n ^ d [1,3].
D i l u khiln Vector ciia D C dflng bp t u thfing dpc tryc N C V C (AFPM) dugc dua tren su khai triln ddng dien tiic thdi ciia stator thanh hai thanh p h i n : Tao luc day keo dpc tryc bdi ddng id (dong dien hudng tryc) va tao mfimen quay dugc bdi ddng iq. Bang each nay, cau true dieu khien cua A F P M trd nen t u a n g ty nhu ciia D C D C .
Hinh 6. Cau true dieu khiin vecia cua DC ddng bd lit thdng doc true NCVC
Duong Quflc Tuin vd Dtg Tap chi KHOA HQC & CONG NGHg Sy djch chuyin cua rotor dpc tryc tir dilm can
b i n g dgc theo fryc z, z cd t h i dugc phat hien bdi cac cdm b i i n khoang each. Vj tri trycphat hien dugc so sanh vdi vi fri true dieu khien 2*
va su chenh lech la dau vao cho bfi dieu khien vi tri tryc Rz. Cac vi tti dieu khien z* lufln ludn dugc thiit lap d l dam bdo rotor la trung dilm giiia hai stator. Dau ra ciia bp dieu khien vi tri tryc dugc sii dung d l tinh toan dong dien qui chilu i*d- Ddng dien qui chieu true rf cho hai cufin day stator i*a! va i^di cd the dugc tao ra bdng each su dyng dong bu Ida nhu sau: i*di = ido + i*d;J*d2 ^ido-i *d- Gia tri cua ddng bu cd the la sd khflng hoac mpt gia tri nho xung quanh khfing.
Tfic dp rotor dupe tao ra tir bd ma hfia dugc so sanh vdi toe do chuan va su chenh lech la d i u vao bp dilu khiln tflc dp R^ Ddu ra cua bp dilu khien tfic do dugc su dyng de tinh toan ddng dien tham chieu true q la /%. Ddng dien tham chieu true q cho hai cupn day stator i*qi vd i*q2 sau do dugc tinh toan giflng nhu ddng id.
Thiit k l d i l u khiln cho DC AFPM se tiln hanh theo cac mach vdng sau day.
Dieu khien d d n g dien
Hdu h i t cac truyen dfing DC xoay chieu hien dai d i u CO cau tnic dieu khien cd mach vdng dilu khien ddng dien ben trong. Do vay, dac tinh cila he truyin dgng phu thugc r i t nhieu vao c h i t lugng ciia chien luge dieu khien ddng dien [ I , 3 , 4 , 5].
Nhiem vu chinh ciia mach vdng dieu khiln ddng dien la nham budc ddng dien trong D C ba pha bam theo cac tin hieu dat. Bang each so sdnh cac dong dien thuc do dugc vdi cdc ddng dien ddt, mach vdng dieu khien ddng dien tao ra cac trang thai chuyen mach cho bien tan nham lam giam sai lech ddng dien.
Do dd, noi chung mach vdng dieu khien dong dien thuc hien hai nhiem v y biJ sai lech (giam sai lech dong dien) va dieu c h l (quyet djnh trgng thai chuyen mach).
Mach vdng dong dien cua DC A F P M nhu tren Hinh 2, tir day ta cd cac cfing thdc:
(11)
l-\-W.W J'L L •('''Krf",d+^.A,''K.''K,%J
1 + W^^Wy^L^L^
WW,
-f-w,i/tCd^K,".d +''^,"<,-J (12)
• J + w^^wy_L^^L^^ Y'^.h^^'J-v., 1(13}
T r o n g d o : W^^ i/R,
i/K
+ j ' "> Ts + l W,^ 2 i _ w =—•—
T.,s + J . Ts + l
Nhin vao (11), (12), (13) t h i hi?n sy tdc dong xen kenh ro ret. De dat dugc ehat lugng moi^- muon nhu ham truyen he kin ciia tieu c h u ^
tfii uu modul t'
K(') =
l-i-2T s 1 .T's'(14) Truo^ het phai tien hanh tach kenh.
Cac bfi dieu chinh tdch kenh dugc xac dinh nhu sau:
K(^)=K(^)i^ - K.(^)r'^'^(') (15)
Khi chpn T^ = r „ =27; = 0,002 se co TJ « * ! cd t h i bfi qua. Khi do cd the xa dinh dugc ham sfl truyen cac khau hieu chinh tach kenh cho mach vong dong dien la:
W„ (.•!) = i-Ji-i-
-)
IRi. « J (16) Khi nghien ciiu md phdng, cac bp bfi dieu
chinh tach kenh nay se dugc ghep noi vao mach ddng dien cua D C tren Hlnh 2.
Dieu lihien dich c h u y e n doc t r u e De don gian, gid thiit r i n g chuyen dgng hudng tam ctia rotor d u g c khong che bdi hai fi dd hudng tam ly tudng. Vi vay, chuy&i ddng dpc tryc la dpc lap vdi chuyen dpng hu'dng tam va co t h i bilu d i l n nhu sau
[1,2,3,4]: F-F^=m2 (17) Trong dd m la khoi lupng cua cac phan
chuyen dgng va F la luc dpc tryc.
Sau do thay (1),(2),(3),(4),(5) vao (17) ta c6:.
m'z + F;^ =A|{/jj-i,j) + ft,(/2^-/i^,)z-A^z ,jg)
92
Duong Qufie Tuin vd Dtg Tap chl KHOA HOC & C 6 N G NGHE 176(16): 8 9 - 9 5
Trong dd A , = 2 ^ V ' ^ ; t ^ = 2 ^ V / ^ So ^p&
De dang thay r i n g h i thong nay khflng on dinh. D l on dinh hda he thdng, mfit bfi d i l u khien vdi thanh phan vi phan dupe su dyng.
Mach v d n g dieu kliiln khodng each tryc dugc bieu dien d hinh Hinh 7.
Hinh 7. Mgch vdng dieu khien khodng cdch true Mach vong dieu k h i l n khoang each true bao gdm ham truyen kin eiia mach v d n g ddng dien ben frong va ham chuyen dgng tryc. Vi tai cua true t h u d n g la khflng biet nen nd dupe xii ly d b u d c thii nhat n h u la mgt nhieu ben ngoai hfi thdng.
D I triet tieu sai leeh ttnh, ta sii dyng bg dieu khiln PID. H a m truyen cua bg dieu khien PID duoc bieu dien n h u sau:
G„is) = K^+-^ + Ki,s (19)
He thflng se fin djnh khi cac tham sfi bp dieu khien thda man:
A", A:, K„{K,K, + K,)
> " (20) fiieu k b i e n toe dp
Dfii vdi t i t ca cac loai DC, sai l?ch giua mfl men dien tii M va mfi men tai My, gay ra gia toe ciia rotor theo dgc tinh c a hgc ciia cac truyen dgng D C . P h u a n g trinh chuyen dgng quay cd t h i d u g c v i i t n h u sau [1,3,4,5]:
dd) (o M-M, =J— hoac =
dl • M-M, (21)
Md men cd t h i dieu khien d u g c bang ddng dien true q n h u bieu diSn d p h u o n g trinh (1) - (5); vi vay, mach v d n g dieu khien tdc dp d u g c b i l u d i l n d hinh Hinh 8.
^v-B^
• ' * •Hinh 8. Mgch vdng dieu khiin tdc dg Tucmg t u n h u mach vdng dieu khien chuyen dieh dpc tryc, mach vdng dieu khien tdc dp ciing bao gfim mgch vong dieu khien ddng dien b6n frong va ham truyen DC efl djnh. Vi tai chua xac dinh nen d budc thu nhat nd d u p e coi nhu la mpt nhieu ngoai he thfing.
Anh h u o n g ciia do ludng tfic dp thudng dugc k i t hop vdi hdng sfi thdi gian t u o n g duong cua mgch vdng dieu khien ddng dien. Ham truyin kin cua he thflng nhu sau:
WM^J^^^^^
I + RJV, sUj + n + KR. (22) Mach vong tpc dp la Ichau tich phan quan tinh nen ta su dung tieu chuan tei tru dpi xung vai ham se truyen chuan:
l + 4T,s Wcis)'
l + 4T,s + 8T:s'+ST's' Can bang (22) va (23) ta c6:
(23)
3(7;'s + I) + KR, ' I + 4T^S + 8T;s' + S T / j ' Chgn: 2T's = T„ giai phuang u-uih tren ta dugc:
„ l+^Ts I I
' KST's KST's 2KT, (24)
DA>M GIA CHAT LUONG BANG M O PHONG So lieu c u a D C v a t h o n g so m o p h o n g R, = 2,3 Q; L,, = 9,6.10'' H; i w = 8,2.10"' H;
T„ = 4,2.10-'; r w = 3,56.10-';y,=0,0126 Wb;
Z , = 1; go = 1,7.10"^ m; m „ „ , = 0,235 kg;
J, = 0,0000082 k g m ' ; ^o = 4ii.lQ-' H/m;
X„,= 5; K,= \;T, = 0,001; «:„ = 0,00417;
T„ = 0,1; T5„ = T„ + 2T,; 2 T ' , = T,„.
Str d o m o p h o n g D C A F P M
n
-IT
Hinh 8. Sa do mo phong
t - 1
fc
•Ducmg Quoc Tuin vd Dtg Tgp chi KHOA HOC & CONG iNOHb Ket qua mo phon^
+ Trudng hgp tfic do dat djnh mii'c n 3000v/ph; m = 0,08 Nm, z = 0
Hinh 11. MdmenDC + Truong hgp tflc do tren dinh muc n = 4000 v/ph; m = 0 , 0 8 N m ; z : i i O .
Hinh 13. MdmenDC
f
Hinh 14. Chuyen dich dgc true z
\ ^
\ / x / \ .
^.rr-ir.-^n;:n:. ,r-,T ,r^
Hinh 12. Do ihi tdc dg tren dtni^ mice
Hinh 15. Dong dien ;',„ vd /jj K E T LUAN
Sir dung DC dong bp tir thong dpc true kich tir nam cham vTnh cuu co cau true dac biet va sir dung c da tir hai diu true nhu tren hinh H J , da tao nen hai mach vong diiu khiin (6c dp va chuyen djch doc true ciia rotpr (o day da coi eac 6 dp tir hai dju true luon luon liili dung chuc nang danh djnh eua no). Bing phuong phap diSu khiln tita thep til' thonj rotpr (T'R), buoc diu da dat duac mot s5 vii de sau:
- Dieu chinh toe dp DC vai toe dp tten djnl
mijrc bang giam tir thong nho bam vao mpt
Duong Qufie Tuin vd Dtg Tgp chl KHOA HQC & C 6 N G NGHE 176(16): 8 9 - 9 5 ddng isd ngugc chieu vdi tir thong cyc yp trong
pham vi dam bao mfl men lam viec cho DC;
- Lufin lufin giir cho rotot d vi trf triing vdi tam cua D C n h d vao mach v d n g d i l u khiln chuyen dieh dgc tryc;
- Cac van de can tiep tuc nghien edu la nang cao chat lugng dieu khien cho D C va dam bao mo men toi u u khi giam t u thfing.
- Tien hanh thi nghiem tren D C A F P M . T A I L I E U T H A M K H A O 1. Nguyen Phung Quang and JOrg-Andreas Dittrich (2008), Vector Control of Three-Phase AC Machines, springer,
2. Akira Chiba, adashi Fukao,Osamu Ichikawa, Masahide Oshima, asatsugu Takemoto and David G. Dorreil (2005), Magnetic Bearings and Bearingless Drives, Newnes.
3. Quang Dich Nguyen and Satoshi Ueno (2010), Analysis and Control of Non-Salient Permanent Magnet Axial-Gap Self-Bearing Motor, IEEE Transactions on Indusfrial Electronics, Vol. PP, No. 99, pp, 1-8, (early access).
4. Nguyen Vdn Liln, Nguyin Manh Tien, Dodn Quang Vinh (2005), Diiu khien DC xoay chiiu cap lit biin tdn bdn ddn, Nxb KHKT.
5. Nguyen Dii'c Qugn (2015), Md hinh hoa, mo phdng vd dieu khien DC lie tra toe do cao. Tap chi KH&CN DH Dd Ndng - S6 11 (96). Quyin 2 6 Nguyin Dodn Phudc (2007), Ly thuyel diiu khiin luyin linh. Nxb KH&KT.
7. Trong Duy Nguyen, Gilbert Foo Hock Beng, King-Jet Tseng, Don Mahinda Vilathgamuwa, and Xinan Zhang (September 2012), Modeling and Position-Sensorless Control of a Dual-Airgap Axial Flux Permanent Magnet Machine for Flywheel Energy Storage Systems, Joumal of Power Electronics, Vol. 12, No. 5.
S U M M A R Y
C O N T R O L D E S I G N F O R AXLAL F L U X P E R M A N E N T M A G N E T S Y N C H R O N O U S M O T O R W H I C H O P E R A T E S
A B O V E T H E N O M I N A L S P E E D
Duong Quoc T u a n ' , Nguyen Nhu Hien, Tran Xuan Minh Thai Nguyen University ofTechnology
When two mechanic bearings ofthe axial flux permanent magnet (AFPM) synchronous motor are replaced by magnetic bearings, the motor can operate at much higher speed above base speed.
There are a lot of industrial applications which require very high speed, however, there are not many researches refer to this issue. One of the way to speed up the motor to the speed above its rated speed is flux weakening ofthe rotor flux ( fp). This paper proposes a solution to increase the motor speed to above base speed by applying a current i^ opposite in direction with the flux IfJ, while maintaining an optimal motor torque. The simulation results prove the correctness of the proposed solution.
Keywords: vi/^PM axial flux permanent magnet synchronous motor, optimal control, above nominal speed, flux -weakening
Ngdy nhgn bdi: 01/11/2917; Ngdy phdn biin: 26/11/2017; Ngdy duyit dang: 05/01/2018
Tel: 0912 269147, Email: duongquoctuan-tdh@tnul edu.vn