bien tan 3pha tiet kiem nang luong

7/23/2019 Bien Tan 3pha Tiet Kiem Nang Luong

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I HC THI NGUYN

TRNG I HC KTHUT CNG NGHIP

NG MINH HONG

NGHIN CU BBIN I NGHCH LU BA PHA

TIT KIM NNG LNG

CHUYN NGNH: TNG HA

LUN VN THC SKTHUT

THI NGUYN - 2012


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I HC THI NGUYNTRNG HKT CNG NGHIP

CNG HA X HI CHNGHA VIT NAMc lp Tdo Hnh phc

THUYT MINH

LUN VN THC SKTHUT

TI:

NGHIN CU BBIN I NGHCH LU BA PHA

TIT KIM NNG LNG

Hc vin : Ng Minh Hong

Lp : CH - K13Chuyn ngnh : Tng ha

CB hng dn khoa hc : PGS.TS. Nguyn NhHin

BAN GIMHIU

KHOA TSAU I HC

CB HNG DN KHOAHC HC VIN

PGS.TS. Nguyn NhHin Ng Minh Hong


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1

LI CAM OAN

Ti l Ng Minh Hong hc vin lp cao hc K13 Tng Ho nin

kho 2010 -2012. Sau hai nm hc tp v nghin cu, c sgip ca cc

thy c gio v c bit l PGS.TS Nguyn NhHin, thy gio hng dn tt

nghip ca ti, ti i n cui chng ng kt thc kho hc thc s.

Ti quyt nh chn ti tt nghip l: "Nghin cu bbin i

nghch lu ba pha tit kim nng lng".

Ti xin cam oan y l cng trnh nghin cu ca cc nhn ti di s

hng dn ca PGS.TS Nguyn NhHin v chtham kho cc ti liu c

lit k. Ti khng sao chp cng trnh ca cc nhn khc di bt khnh thc

no. Nu c ti xin chu hon ton trch nhim.

Ngi cam oan

Ng Minh Hong


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2

MC LC

Trang

Li cam oan 1

Mc lc 2Danh mc cc k hiu v chvit tt 5

Danh mc cc hnh v 8

Mu 10

CHNG I

GII THIU VBIN TN BA PHA

12

1.1. Gii thiu vbin tn sdng in tcng sut 12

1.1.1. Bin tn 121.1.2. Bbin tn trc tip 13

1.1.3. Bbin tn gin tip 17

1.1.3.1. Bbin tn gin tip dng chnh lu iu khin 18

1.1.3.2. Bbin tn dng chnh lu khng iu khin c thm b

bin i xung p 19

1.1.3.3. Bbin tn dng bchnh lu khng iu khin vi b

nghch lu PMW 20

1.1.3.4. Bin tn iu khin vector 21

1.2. Bin tn ba pha 23

1.2.1. Gii thiu chung 23

1.2.2. Bin tn ba pha trc tip 23

1.2.3. Bin tn ba pha gian tip 25

1.3. La chn hng ng dng cho hthng truyn ng sdng bin tn

ba pha

26

1.3.1. La chn bin tn 26

1.3.2. La chn ng c 28

1.3.3. La chn phti 29


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3

1.3.3.1. Chlm vic ca ti 30

1.3.3.2. Cc yu cu vtruyn ng in 32

1.3.3.3. Yu cu vdng chnh xc, tit kim nng lng v an ton. 33

1.3.3.4. Tnh chn cng sut ng c 35

1.4. Kt lun 38

CHNG II

NGHIN CU HTHNG BIN TN BA PHA

- NG CKHNG NG BROTOR LNG SC 40

2.1. M hnh ton hc nhiu bin ca ng ckhng ng bba pha 40

2.1.1. c im ca m hnh ton hc trng thi ng ca ng c

khng ng b 402.1.2. M hnh ton hc nhiu bin ca ng cKB ba pha 42

2.1.2.1. Phng trnh in p 43

2.1.2.2. Phng trnh tthng 44

2.1.2.3. Phng trnh chuyn ng 48

2.1.2.4. Phng trnh m men 48

2.1.2.5. M hnh ton hc ng ckhng ng bba pha 49

2.2. Gii thiu viu khin tn sng ckhng ng b 50

2.2.1. iu khin v hng (SFC: Scalar Frequency Control) 51

2.2.2. iu khin nh hng theo ttrng (FOC: Field Oriented

Control) 52

2.2.3. iu khin trc tip mo men (DTC: Direct Toque Control) 57

2.3 Kt lun 58

CHNG III

KHO ST CHT LNG HTHNG BIN TN BA PHA

NG CKHNG NG BCHO CABIN THANG MY 59

3.1. Phn tch h truyn ng bin tn ng c khng ng b cho

Cabin thang my 59


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3.1.1. Khi mch lc 59

3.1.2. Khi iu khin 60

3.2. Cc thng schyu ca htruyn ng bin tn ASM 64

3.2.1. ng cASM 64

3.2.2. Sliu vbin tn 64

3.3. Sm phng v cc kt qu 65

3.3.1. Sm phng hthng v sminh ha chi tit: 65

3.3.2. Cc kt qum phng 71

3.4. Kt lun 73

K

T LU

N V KI

N NGH 74

TI LIU THAM KHO 75


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5

DANH MC CC K HIU V CHVIT TT

x(t), x Gi trtc thi

X*, x

*Gi trt

Gc pha ca vector chun

Hscng sut

Gc pha dng in

Vn tc gc

Gc pha

Gc pha iu khin

cos Hscng sut cbn

f Tn s

i(t), i Gi trdng in tc thi

j n vo

X, x Sai lch

kP, kI Hskhuych i, hstch phn

p(t), p Cng sut tc dng tc thi

q(t), q Cng sut phn khng tc thi

t Gi trthi gian tc thi

v(t), v Gi trin p tc thi

L Vector tthng o

L Thnh phn vector tthng o trn htrc to-

L Thnh phn vector tthng o trn htrc to-

Ld Thnh phn vector tthng o trn htrc tod - q

Lq Thnh phn vector tthng o trn htrc tod - q

uL Vector in p li

uL Thnh phn vector in p li trn htrc to-

uL Thnh phn vector in p li trn htrc to-


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uLd Thnh phn vector in p li trn htrc tod - q

uLq Thnh phn vector in p li trn htrc tod - q

iL Vector dng in li

iL Thnh phn vector dng in li trn htrc to-

iL Thnh phn vector dng in li trn htrc to-

iLd Thnh phn vector dng in li trn htrc tod - q

iLq Thnh phn vector dng in li trn htrc tod - q

uS, uconv Vector in p vo bchnh lu

uS Thnh phn vector in p vo bchnh lu trn htrc to-

uS Thnh phn vector in p vo bchnh lu trn htrc to-

uSd Thnh phn vector in p vo bchnh lu trn htrc tod - q

uSq Thnh phn vector in p vo bchnh lu trn htrc tod - q

udc Gi trin p mt chiu

idc Gi trdng in mt chiu

Sa,Sb,Sc, Trng thi ng ct ca bbin i

C Gi trtin

I Gi trhiu dng ca dng in

L Gi trin cm

R Gi trin tr

S Cng sut biu kin

T Chu k

P Cng sut tc dng

Q Cng sut phn khng

Z Tng trkhng4Q Bn gc phn t(vit tt ca Four(4) Quater)

DPC iu khin trc tip cng sut (vit tt ca Direct Power Control)

DTC iu khin trc tip mmen (vit tt ca Direct Toque Control)

DPF Hscng sut dch chuyn (vit tt ca Displacement Power Factor)


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FOC iu khin ta ttrng (vit tt ca Field Oriented Control)

PF Hscng sut (vit tt ca Power Factor)

PWM iu chrng xung (vit tt ca Pulse Width Modulation)

Te Mmen in t

VOC iu khin ta theo in p li (vit tt ca Voltage Oriented Control)


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8

DANH MC CC HNH V

Hnh 1.1: Mt shnh nh vbin tn 12Hnh 1.2: Skhi quy trnh iu khin tc ng csdng PLC

kt ni bin tn 13Hnh 1.3: Thit bbin tn trc tip 14Hnh 1.4: Snguyn l bbin tn trc tip 14Hnh 1.5:thin p u ra ca thit bbin tn xoay chiu xoay chiu

hnh sin 15Hnh 1.6: Sng hi bc nht dng, p trn ti v cc chlm vic ca

cc khu trong bin tn trc tip 17Hnh 1.7: Thit bbin tn gin tip 18

Hnh 1.8: Bbin tn gin tip c khu trung gian mt chiu 19Hnh 1.9: Bbin tn iu khin vector 22

Hnh 1.10 : Cu trc bin tn ma trn ba pha trc tip 24Hnh 1.11: Cu trc bin tn ma trn gin tip ba pha 25

Hnh 1.12 Chlm vic ca Cabin thang my 31Hnh 1.13: Cc ng cong biu din sphthuc ca qung ng S,

tc v, gia tc a v dt theo thi gian. 32Hnh 2.1: Scu trc iu khin nhiu bin ca ng ckhng ng b 41Hnh 2.2: S cu trc iu khin h thng iu tc bin tn ca ngc

khng ng bnhiu bin 42Hnh 2.3: M hnh vt l ng ckhng ng bba pha 43Hnh 2.4: Cu trc iu khin v hng h truyn ng bin tnng c

khng ng b 51Hnh 2.5: Scu trc bin i ta ng ckhng ng b 54Hnh 2.6: tng cu trc hthng iu khin vect 55Hnh 2.7 : Cu trc iu khin vectca h truyn ng bin tn ng c

ng bkch tnam chm vnh cu 56Hnh 2.8: Skhi hbin tn ng ckhng ng b, iu khin trc tip

mmen. 58

Hnh 3.12: S nguyn l phn lc truyn ng bin tn ng c khngng brotor lng sc 59

Hnh 3.13: Cu trc khi iu khin chnh lu PWM theo VOC 61Hnh 3.14: Cu trc khi iu khin nghch lu ca htruyn ngbin tn ng ckhng ng b rotor lng sc 63

Hnh 3-15: Sm phng hbin tn 4Q - ng ckhng ng bba pharotor lng sc iu khin theo VOC - DTC 65

Hnh 3-16: Trin khai chi tit khi PLECS Circuit 66Hnh 3-17: Trin khai chi tit khi IGBT Converter 66Hnh 3-18: Thng sng cASM 67


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Hnh 3-19: M tton hc ng cASM 68Hnh 3-20: Khi iu khin PWM 68Hnh 3-21: Khi Current Control 69Hnh 3-22: Khi Voltage Control 69Hnh 3-23: Khi Inv_Motor 70

Hnh 3-24: Khi Inv_Motor/ Direct Torque Control 70Hnh 3-25: Khi Inv_Motor/ Speed Control 71Hnh 3-26.thtc ca Cabin 71Hnh 3-27.thm men ca Cabin 72Hnh 3-28.thtc v m men ca Cabin 73


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LI NI U

Ngy nay vi spht trin nhanh chng k thut in t, tin hc v t

ng ha, nn cng nghip nc ta ang tng ngy hi nhp vi nn kinh tth

gii v tip nhn nhng thnh tu mi nht ca khoa hc v cng ngh. y l

nhng yu cu v thch thc i hi i ngcc nh khoa hc kthut v cng

nhn trong nc phi khng ngng hc tp tip cn v lm chnhng cng

nghtin tin ca thgii.

Sau 2 nm c o to thc s to trng i hc K thut Cng

nghip, ti c giao ti lun vn tt nghip l Nghin cu bbin inghch lu ba pha tit kim nng lng. i tng nghin cu l htruyn

ng bin tn ba pha - ng ckhng ng brotor lng sc cho ph ti th

(Cabin thang my).

Lun vn gm c 3 chng:

Chng I : Gii thiu vbin tn ba pha.

Chng II : Nghin cu htruyn ng bin tn ba pha ng ckhng

ng brotor lng sc.

Chng III : Kho st cht lng htruyn ng bin tn ba pha - ng

ckhng ng brotor lng sc cho cabin thang my.

ti c hon thnh, ngoi sn lc ca bn thn cn c s ch

bo, gip ng vin ca cc thy c gio, gia nh, bn b v ng nghip.

Ti xin gi li cm n su sc nht n PGS.TS Nguyn NhHin , ngi

lun quan tm ng vin, khch lv tn tnh hng dn ti trong sut qu trnh

thc hin lun vn. Chn thnh cm n thy.


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Cc vn c cp n trong quyn lun vn ny chc chn khng

trnh khi thiu st, ti rt mong nhn c nhng kin ng gp tcc thy

c v cc bn ng nghip.

Xin trn trng cm n!


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12

CHNG I

GII THIU VBIN TN BA PHA

1.1. Gii thiu vbin tn sdng in tcng sut1.1.1.Bin tn

Bbin i tn shay cn gi l bbin tn l thit bbin i dng in xoay

chiu tn s ny thnh dng in xoay chiu c tn skhc m c ththay i

c.

i vi cc bbin tn dng cho vic iu chnh tc ng cxoay chiu th

ngoi vic thay i tn s, chng cn c ththay i cin p ra khc vi in p

li cp vo bbin tn.

Bbin tn chia lm hai nhm :

- Bin tn my in : sdng my in xoay chiu lm bin i tn sngun

in.

- Bin tn sdng in tcng sut ( bin tn van) : dng cc tn hiu iu

khin ng mcc van ( thng l tiristor hay transistor) bin i dng in xoay

chiu tn sny thnh dng in xoay chiu c tn skhc

Hnh 1.1. Mt shnh nh vbin tn


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13

Bin tn van thng c chia thnh hai loi :

- Bin tn trc tip

- Bin tn gin tip

Bin tn van c ng dng rng ri v c nhiu u im nhkch thc nh

nh, khng gy n, hskhuch i cng sut ln, hiu sut cao.

1.1.2

Bin tn trc tip

Bin tn trc tip l bbin i tn strc tip tli in xoay chiu khng

thng qua khu trung gian mt chiu. Bbin tn ny thng dc dng

cho truyn ng c cng sut ln, tc lm vic thp.

Hnh 1.2. Skhi quy trnh iu khin tc ng csdng

PLC kt ni bin tn


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Cu trc ca bbin tn ny nhhnh 1.3, trong chcn dng mt bbin

i l c thbin i ngun in xoay chiu c in p v tn skhng i thnh

in p xoay chiu c in p v tn siu chnh c.

Bbin tn gm hai bchnh lu ni song song ngc nhhnh 1.4. Cc b

chnh lu ny c thl sba pha c im trung tnh, scu hoc cc bchnh

lu nhiu pha. Spha ca bchnh lu (m) cng ln th thnh phn sng iu ha

bc cao cng gim.

Nguyn l lm vic ca bbin tn nhsau:

Mi mt pha u ra ca bbin tn trc tip u c to ra bi mch in mc

song song ngc hai schnh lu tiristor. Hai schnh lu thun ngc ln

lt c iu khin lm vic theo chu knht nh. Trn phti snhn in p ra

xoay chiu U1 . Bin ca n phthuc vo gc iu khin ,cn tn sca n

phthuc vo tn skhng chqu trnh chuyn i slm vic ca hai schnh

lu mc song song ngc. Nu gc khng thay i th in p trung bnh u ra c

BIN TN

~3

U 1 ,f1

~3

U 2 ,f2

Hnh 1.3: Thit bbin tn trc tip

Ti~3U ,f

~3

U 2 ,f2

Hnh 1.4 : Snguyn l bbin tn trc tip


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scn tng cng ti 36 tiristor ( mi nhnh cu chdng mt tiristor ) nu dng lai

stia ba pha, cng phi dng ti 18 tiristor. V vy thit bbin tn trc tip tuy

vmt cu trc chdng mt khu bin i nhng slng linh kin li tng ln rt

nhiu khin cho tng kch thc tng ln rt ln. Do nhng thit bny u tng t

nhthit bca bbin i c o dng thng dng trong hthng iu khin iu

tc mt chiu c o chiu nn qu trnh chuyn mch chiu dng in c thc

hin ging nhtrong schnh lu c iu khin (chuyn mch tnhin) i vi

cc linh kin khng c yu cu g c bit. Ngoi ra thnh 1.5 c ththy, khi in

p i chiu thhnh sin ca in p ngun cng c thbin i theo rt nhanh

chng, v vy tn su ra ln nht cng khng vt qu 1/3 -1/2 tn sli in (

ty theo spha chnh lu ) nu khng thu ra sthay i rt ln, snh hngti s lm vic bnh thngca h thng iu tc bin tn. Do s lng linh kin

tng nhiu tn su ra gim xung, phm vi thay i tn su ra ca bbin tn

hp (v cng bgii hn ctn sthp nht) nn hiu tc ny t c sdng, ch

trong mt slnh vc yu cu cng sut ln v tc lm vic thp, chng hn nh

my cn thp, my nghin bi, l xi mng nhng loi my ny khi dng ng c

tc thp c cp in bi bin tn trc tip c thloi bc hp gim tc rt

cng knh v thng tiristor mc song song ngc mi tha mn c yu cu cng

sut ra. Bbin tn trc tip tuy c mt snhc im l slng phn tnhiu

,phm vi thay i tn skhng rng , cht lng in p ra thp nhng c u im

l hiu sut cao hn so vi cc bbin tn gin tip, iu ny c bit nghkhi

cng sut h thng iu tc cc ln ( cc h thng dng ng c cng sut n

16.000 KW). Trn thdng sng hnh 1.6 ta thy cng sut tc thi ca bin tn

bao gm c bn giai on.


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Trong hai khong ta c tch in p v dng in ca bin tn dng, bin tnly cng sut tli cung cp cho ti. Trong hai khong cn li ta c tch in p v

dng in ca bin tn m nn bin tn bin i cung cp li cng sut cho li.

1.1.3 Bbin tn gin tip

Bbin tn trc tip c u im l c ththit kvi mt cng sut kh ln

u ra v hiu sut cao nhng cng tn ti mt snhc im nh:

- Chto ra in p xoay chiu u ra vi tn sthp hn tn sin p li.

- Kh iu khin tn scn khng v khi tn hao sng hi trong ng c

kh ln.

- tinh v chnh xc trong iu khin khng cao.

- Sng in p u ra khc xa hnh sin.

\

Hnh 1.6: Sng hi bc nht dng, p trn ti v cc chlm vic ca

cc khu trong bin tn trc tip


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Chnh v nhng c im trn m mt loi bin tn khc c a ra nng

cao cht lng h thng truyn ng bin tn ng cxoay chiu l bin tn

gin tip . Bbin tn gin tip cho php khc phc nhng nhc im ca bbin

tn trc tip.

Bbin tn gin tip c khu trung gian 1 chiu nn c thc cc cu trc

khc nhau, cu trc chung uc m tnhhnh 1.7. Vcbn c thc ba khu

chnh : chnh lu, lc v nghch lu. Phthuc vo vic iu chnh in p u ra

m c thc ba dng sau : Bbin tn dng chnh lu c iu khin , bbin tn

dng chnh lu khng iu khin nhng thm bbin i xung p 1 chiu, bbin

tn dng chnh lu khng iu khin vi nghch lu thc hin iu chrng xung( PWM).

1.1.3.1. Bbin tn gin tip dng chnh lu iu khin

Bbin tn c cu trc nhhnh 1.8a, in p xoay chiu li in c bin

i thnh in p 1 chiu c iu chnh nhchnh lu iu khin tiristor, khu lc c

thl blc in dung hoc in cm phthuc vo dng nghch lu yu cu, khi

nghch lu c thsdng cc tiristor hoc transistor. Vic iu chnh gi trin p

ra U 2 oc thc hin bng vic iu khin gc iu khin bchnh lu, vic iu

chnh tn stin hnh bi khu nghch lu, tuy nhin qu trnh iu khin c phi

hp trn cng mt mch in iu khin. Cu trc ca bbin tn loi ny n gin,

diu khin nhng do khu bin i in p xoay chiu thnh 1 chiu (u vo) s

dng chnh lu iu khin tiristor nn khi in p ra thp th hscng sut gim

Hnh 1.7: Thit bbin tn gin tip


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thp, khu bin i in p hoc dng in 1 chiu thnh xoay chiu (u ra) thng

dng nghch p ba pha bng tiristor nn sng hi bc cao trong in p xoay chiu

u ra thng c bin kh ln. y l nhc im chyu ca loi bin tn ny.

1.1.3.2. Bbin tn dng chnh lu khng iu khin c thm bbin i

xung p

Bbin tn xoay chiu gin tip dng bchnh lu khng iu khin kt hp

vi bin i xung in p mt chiu iu chnh in p mt chiu u vo khi

nghch lu c biu din nhhnh 1.8b.*

Vic bin i in p xoay chiu thnh mt chiu cp cho khi nghch lu

sdng bchnh lu it khng iu khin. Khi nghch lu chc nhim vbin

i in p mt chiu thnh xoay chiu vi tn siu chnh c m khng c kh

nng iu chnh in p ra ca nghch lu nn gia khi chnh lu v nghch lu b

Hnh 1.8: Bbin tn gin tip c khu trung gian 1 chiu

a. Bin tn dng chnh lu iu khin bng tiristor

b. Bin tn dng chnh lu khng iu khin c thm bbin i xung p

c. Bin tn dng chnh lu khng iu khin vi nghch lu iu chPWM


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tr thm bbin i xung in p 1 chiu iu chnh gi trin p 1 chiu cp

cho nghch lu nhm thc hin nhim viu chnh gi trhiu dng in p xoay

chiu u ra nghch lu U 2 . Mc d bbin tn ny phi thm vo mt khu (

cha kkhu lc) nhng h scng sut u vo kh cao, khc phc c nhc

im ca bbin tn thnht. Khi nghch lu u ra khng thay i nn vn tn ti

nhc im l cc sng hi bc cao c bin kh ln.

1.1.3.3. Bbin tn dng bchnh lu khng iu khin vi bnghch

lu PMW

Nh trnh by, trong hthng iu tc bin tn p dng phng php iu

chnh tsin p tn skhng i, khi sdng bin tn gin tip dng tiristor th

vic iu chnh in p v tn sc thc hin ring hai khu : iu chnh tn skhu nghch lu cn iu chnh in p thc hin khu chnh lu, iu ny

ko theo mt svn l :

- Mch in chnh c hai khu cng sut iu khin c ngha l kh phc tp

- Do khu mt chiu trung gian c blc bng tlc hoc in khng vi qun

tnh ln, lm cho tnh thch nghi trng thi ng ca hthng thng bchm tr.

- Do bchnh lu c iu khin lm cho hscng sut ca ngun in cung

cp gim nhkhi cng sut u ra gim xung theo sthay i ca chlm vic

ca hiu tc, ng thi lm tng sng hi bc cao trong dng in ngun.

- u ra ca bnghch lu l in p (dng in) c dng khc xa hnh sin, to

ra nhiu sng hi bc cao trong dng in ng c, dn ti m men bin ng kh

ln nh hng ti tnh n nh lm vic ca ng c, c bit l khi tc thp.

V vy cc thibin tn do cc linh kin in t cng sut dng tiristor khng th

p ng c nhng yu cu i vi nhng hthng iu tc bin tn hin i. S

xut hin cc linh kin in tcng sut iu khin hon ton (GTO,IGBT,) cng

vi spht trin ca kthut vi in t to ra cc iu kin tt gii quyt vn

ny.

Bbin tn PWM ng dng kthut iu chtrong hthng thng tin vo vic

iu chin p ra ca bin tn vcbn gii quyt c vn tn ti trong b


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bin tn thng thng dng tiristor, to iu kin cho spht trin lnh vc mi l

hthng iu tc dng in xoay chiu cn i. Hnh 1.8c gii thiu cu trc bbin

tn PWM, bbin tn ny vn l bbin tn c khu trung gian mt chiu chkhc

l khu chnh lu chcn l chnh lu khng iu khin, in p ra ca n sau khi i

qua blc C (hoc L-C) cho in p mt chiu c gi trkhng i dng cp cho

khu nghch lu, linh kin ng mcng sut trong khu nghch lu l cc phn t

iu khin hon ton v c iu khin ng ct vi tn skh cao, to nn trn

u ra mt lot xung hnh chnht vi rng khc nhau, cn phng php iu

khin quy lut phn b thi gian v trnh t thao tc ng ct chnh l phng

php iu chrng xung. y thng qua vic thay i rng cc xung ch

nht c thiu chgi trbin in p ca sng cbn u ra nghch lu, png yu cu phi hp gi triu khin tn sv in p ca hiu tc bin tn.

c im chyu ca mch in ny l :

- Mch in chnh chc mt khu cng sut iu khin c, n gin ha cu

trc, hscng sut ca mng in khng lin quan ti bin ca in p u ra

bnghch lu v tin gn n 1.

- Bnghch lu thc hin ng thi iu tn v iu p, khng lin quan n

tham s ca linh kin khu trung gian mt chiu nn lm tng tc ng nhanh

trng thi ng ca hthng.

- C thnhn c thin p u ra tt, hn chhoc lai bc sng hi

bc thp, lm cho ng cc thlm vic vi in p bin thin gn nhhnh sin,

bin ng ca m men kh nh, m rng phm vi iu chnh tc ca h thng

truyn ng.

1.1.3.4. Bin tn iu khin vector

Vi sra i ca cc linh kin bn dn cng sut iu khin hon ton dn n

vic xut hin nghch lu iu chrng xung hnh sin ( SPWM) ci thin mt

bc cht lng iu tc ng cxoay chiu. Cc bin tn SPWM vi phng php

iu chnh U 1/fs = hng s(fs l tn ssng hi cbn in p t vo mch stator

ng c, y cng chnh l tn sf2 trong cc shnh 1.8 v 1.9 ) c thcho php


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iu chnh tc ng cxoay chiu vi cht lng dng p kh tt, phm vi iu

chnh c mrng nhng m men cc i bgii hn v cha p ng c cc

yu cu cao vcht lng tnh ca phn ln cc hiu tc. Vi cc hiu tc

vng kn dng bin tn gin tip SPWM nhl hiu tc iu khin tn strt

chng hn, ci thin ng kcht lng tnh ca hthng iu tc ng cxoay

chiu, to c c tnh gn vi h thng iu tc hai mch vng ng c mt

chiu, tuy nhin cht lng ng ca h thng vn cn xa mi t c nh h

thng iu tc hai mch vng ng cmt chiu.

Da vo kt qunghin cu, cc nh sng ch to nn h thng iu tc

bin tn iu khin vector m ngy nay c ng dng rt phbin

Cu trc phbin phn lc ca bin tn sdng nghch lu iu khin vector

c m tnhhnh 1.9. Vcbn cc thit bphn lc ca bin tn ny hon ton

tng tnhca bin tn iu chng rng xung hnh sin, chkhc l vic iu

khin khi nghch lu p dng phng php iu khin vector. Trong bin tn iu

khin vector, ngi ta p dng php bin i ta khng gian cc vector dng, p,

tthng ng ctha-b-c sang hhai pha quay d-q, quay ng bvi ttrng

stator ca ng cv thng chn trc d trng vi vector tthng rotor (iu khin

hng theo ttrng stator). Thng qua php bin i ta khng gian vector, cc

i lng dng p xoay chiu hnh sin ca ng ctrthnh i lng mt chiu

nn hon ton c thsdng cc kt qunghin cu tng hp hthng truyn ng

ng cmt chiu thit kcc biu chnh. Sau , cc i lng mt chiu

u ra cc biu chnh li c bin i thnh i lng xoay chiu ba pha qua

php bin i ngc ta khng ch thit b pht xung iu khin cc van

nghch lu. Htruyn ng in bin tn vector- ng cxoay chiu c thc hin

Hnh 1.9: Bbin tn iu khin vector


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dng hvng kn vi vic iu khin nh hng theo ttrng rotor cho php c

thduy tr c t thng rotor khng i (vng tn s thp hn tn s cbn),

thc hin c quan hE r= fs = hng s, nh m c tnh cca ng cxoay

chiu khng ng b trong h c dng nhc tnh ng cmt chiu ( vi khnng qu ti m men rt ln).

1.2. Bin tn ba pha

1.2.1. Gii thiu chung

Cc bbin tn thng thng lun tn ti mt snhc im cbn nh :

sng iu ha bc cao gy mo in p li, hscng sut thp , mt sbin tn

cho cht lng iu khin tt khi dng trung tnh bng khng nhng trong trng

hp ngun ti khng cn th li khin cht lng iu khin khng tt c thgy raschthng.

Bin tn ba pha bn dy c pht trin trn cschnh lu ba pha ba dy

khc phc nhng nhc im ca h thng ny khi lm vic vi ngun khng cn

bng, thng qua vic trn mch lc c thm mt cp van bn dn iu khin

dng trung tnh. Nh vy chng c kh nng lm vic tt trong iu kin ngun

khng cn bng.

1.2.2. Bin tn ba pha trc tip

Bin tn ma trn ( matrix converter MC ) l bbin i trc tip AC AC

c nhiu u im nhtrao i cng sut theo hai chiu, dng in u vo c dng

hnh sin, hscng sut u vo gn bng mt. Bin tn ma trn trc tip ba pha

bn dy ( TFDMC) c chra trn hnh 1.10u vo c ba nhnh, u ra c bn

nhnh, ba nhnh cho ba pha, mt nhnh cho dy trung tnh, cu trc ny ng ng

c cc yu cu cho cc phti cn sdng dy trung tnh.


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Chuyn mch l qu trnh chuyn dng in tmt van bn dn ang bkha

li sang mt van khc va mra. Khc vi bin tn truyn thng, cc van bn dn

hai chiu trong bin tn ma trn yu cu qu trnh chuyn mch tng i phc tp.

Qu trnh chuyn mch trong bin tn ma trn tun ththeo hai quy tc, l khng

c ngn mch pha li v khng c hmch pha ti. Quy tc thnht m

bo khng xy ra ngn mch pha in p li gy ra xung dng in ln ph hy

van. Quy tc thhai m bo khng gy ra hin tng hmch pha ti gy ra qu

in p, nh thng cc van bn dn. Nhiu phng php chuyn mch c

nghin cu v p dng cho bin tn ma trn nh chuyn mch bn bc, chuyn

mch hai bc, chuyn mch mt bc,chuyn mch thng minh.

Hnh 1.10 : Cu trc bin tn ma trn ba pha trc tip


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Do qu trnh chuyn mch din ra rt nhanh nn logic chuyn mch thng

c thc hin trn cc thit bphn cng nhl CPLD, FPGA. Logic ca qu trnh

chuyn mch rt phc tp nn m bo tnh chnh xc ca cc trng thi logic,

trc khi thnghim trn phn cng cn phi tin hnh m phng kim chng.

1.2.3. Bin tn ba pha gin tip

Bin tn ma trn ( matrix converter MC ) l bbin i trc tip AC AC

c nhiu u im nhtrao i cng sut theo hai chiu, dng in u vo c dng

hnh sin, hscng sut u vo gn bng mt.

MC c vai tr l bbin i cng sut khi lm vic vi ng cth c im

ca ti l i xng. MC c vai tr l bngun th c im v tnh cht ca ti srt

a dng, c thl mt, hai, ba pha, ng c, R, L, C, tuyn tnh hoc phi tuyn.

y cp n mt trong nhiu phng n c thp ng c cc yu cu trn,

cu trc mch lc cp c chra trn hnh 1.11,n bao gm hai phn, phn ni

vi li sdng chnh lu hai cc tnh ni theo kiu ma trn vi sau van bn dn hai

chiu BSD, phn ni vi ti sdng nghch lu bn nhnh thng thng.

Hnh 1.11. Cu trc bin tn ma trn gin tip ba pha


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1.3. La chn hng ng dng cho h thng truyn ng s dng

bin tn ba pha

Hin nay h truyn ng hin i thng c dng trong thang my l

iu khin tn sng ckhng ng bv gn y nht bt u sdng ng

cng bkch tnam chm vnh cu. nh hng ca ti ny l ng dng

bin tn ba pha ng ckhng ng bcho cabin thang my.

1.3.1. La chn bin tn

Cc bbin tn c chia thnh 2 loi chnh:

+ BBT phthuc (hay BBT trc tip cycloconverter) ; loi ny bin i

thng dng in xoay chiu tn sf1thnh f2khng qua khu chnh lu CL nn

hiu sut cao hn loi trn nhng vic thay i tn sra kh khn v phthucvo tn sf1

+ BBT c lp (hay BBT gin tip autonom inverter) hay cn gi l

BBT trung gian.

Trong BBT loi ny, dng in xoay chiu u vo tn sf1c chnh

lu thnh dng in mt chiu (tn s f = 0), lc ri li c bin i thnh

dng xoay chiu tn sf2.

Hin nay chdng BBT gin tip (BBT trung gian) vi bchnh lu dng

Diode v Tiristor.

~ f1,U1 ~ f2,U2

~f2

~f1

=

=

BBT BCL BB MCXCF

~f1,U1

~f1

~f2

BBT

~f2,U2


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Chnh lu l qu trnh bin i nng lng dng in xoay chiu thnh

nng lng dng in mt chiu, c in p n nh v cht lng cao. Chnh

lu c phn loi theo nhiu cch: theo spha ngun cp cho mch van (3

pha, 6 pha), theo loi van bn dn (chnh lu khng iu khin, chnh lu iu

khin, chnh lu bn iu khin) v phn loi theo smc van (hnh tia, hnh

cu).

Bchnh lu diode v tiristor c lch sgn nm mi nm v chng

c nh ngha nhmt thit bin tcng sut cin, c ng dng rng

ri nht trong thc t.

u im: Chnh lu diode v tiristor c cc u im nh: n gin, bn

v gi thnh thp.Nhc im: - Dng in cha nhiu sng iu ho bc cao lm nh

hng n cht lng in nng.

- Gy ra hscng sut thp.

- Cc b chnh lu dng diode v thyristor chdn nng lng

theo mt chiu dn n kh trao i nng lng gia ng cv li. V vy,

nng lng khng thc trvli tng cm btiu hao trn cc in

trc iu khin bi cc ngt in ni dc theo mch mt chiu. Phng

php ci tin vn ny l dng hm dp nng lng mch mt chiu hoc

dng bchnh lu lm vic chnghch lu trvli.

Do cc nhc im ca bchnh lu ci hi phi tm ra mt bchnh

lu mi thomn cc iu kin:

-Cha t sng iu ho bc cao.

-Hscos cao.

-Nng lng chy c theo theo hai chiu.

Nhvy vn t ra y l phi tm ra mt loi chnh lu tn tho

mn nhng yu cu nu trn.

Nhng nm gn y ngi ta a ra cu trc bin tn sdng bchnh

lu PWM khc phc nhng nhc im trn. Bin tn ny c thhot ng


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trn cbn gc phn tnn cn gi l bin tn 4 gc phn t(4Q). Sra i

ca loi bin tn ny mang li mt gii php k thut mi vi nhiu u im

vt tri so vi cc loi bin tn ngun p thng thng.

1.3.2. La chn ng c

a. ng ckhng ng b(ASM Asynchronous Machine)

ng ckhng ng bc kt cu n gin, chc chn, vn hnh an ton

v sdng ngun cung cp trc tip tli in xoay chiu ba pha. Tuy nhin,

vn iu khin ng cxoay chiu ni chung v ng ckhng ng bni

ring phc tp hn ng cmt chiu v srt phc tp nu i hi hiu xut

cao. Nguyn nhn cbn l c nhiu quan hphi tuyn (n, M, I), xl phc tp

cc tn hiu hi tip, iu khin phc tp ngun cung cp c in p v tn sbin thin. V vy, trc y cc htruyn ng in ng ckhng ng bba

pha c iu chnh tc chim tlt so vi ng cmt chiu. Trong thi gian

gn y do spht trin ca cng nghchto bn dn cng sut v k thut

in ttin hc cng vi nhng thnh tu trng vic nghin cu l thuyt iu

chnh tng ng cxoay chiu, nhng u thca ng ckhng ng b,

c bit l ng crto lng sc so vi ng cmt chiu vmt kt cu, vn

hnh v sa cha c khai thc trit . Xu thhin nay l ng dng iu

khin vectvo cc hiu khin chuyn ng.

Cc hthng iu chnh tc ng cxoay chiu c yu cu cao vgii

iu chnh v tnh cht ng hc chc ththc hin c vi cc bbin tn.

Cc hny sdng ng ckhng ng broto lng sc c kt cu n gin,

vng chc, gi thnh r, c thlm vic trong mi mi trng phc tp. Trong

lnh vc iu khin thang my, phng n truyn ng sdng ng c lng

sc iu khin bng bin tn iu khin ng ctruyn ng cabin hin nay

ang l phng n c sdng rng ri nht thay thcho cc phng n dng

ng c mt chiu v ng c rto dy qun, c th thay i kh nng khi

ng v hm nhm gim git cho cabin, iu chnh tc trn hon ton,

cht lng iu chnh cao, ddng vn hnh.


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b. ng cng b

ng cng b ba pha, trc y thng dng cho loi truyn ng

khng iu chnh tc , cng sut ln hng trm KW n hng MW (truyn

ng cho my bm, my nn kh, qut gi, my nghin,). Ngy nay, do s

pht trin mnh mca cng nghip in t, cng nghip vt liu, ng c

ng bc nghin cu ng dng nhiu trong cng nghip, mi di cng

sut t vi trm W (truyn ng n dao trn my ct kim loi, dn ng cc

khp ca tay my,), n hng MW (truyn ng ko tu cao tc TGV, my

nghin, my cn thp,).

ng cng b lun lun m bo quay ng bv cng tn svi

ngun in, chcn ngun in gic in p v tn stuyt i khng i.Thit bc kch thc nhnhchic ng hquay nh gi, ln n mc nh

cc ng cng bcln trong hthng my pht mt chiu u sdng c

im quay vi tc gc khng i.

ng cng bcn c mt u im ni bt l c thiu chnh c

hscng sut cun bng cc phng php kch t, c thlm cho hscng

sut cao hn 1 (cos1). Trong mt nh my chcn sdng mt vi ng c

ng bvi dung lng rt ln truyn ng cho cc phti yu cu tc bt

bin (chng hn nhmy bm, my nn kh) l c thci thin c cng sut

ca ton nh my.

ng cng b(c bit l loi cng sut ln) khi khi ng rt phc

tp, lc nghim trng c thpht sinh dao ng mnh in p ca li in gy

ra nguy him cho li in, cho cc phti ln cn v cho chnh ng cng

b. Ngoi ra, cc vn dao ng v mt ng bkhi ti trng ln cng cn l

trngi khi sdng ng cng b. V vy, trkhi c nhng yu cu c

bit, cc thit bcng nghip ni chung rt t dng n ng cng b.

1.3.3. La chn phti

1.3.3.1. Chlm vic ca ti


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Cabin thang my hnh khch chuyn ng theo phng thng ng v

c trt theo cc rnh nh hng. M men ca ng c truyn ng cho

cabin thang my cng thay i theo ti trng rt r rt, khi khng ti m men

ng ckhng vt qu (15 20)% Mm. Do , sdng ti u vm men

v cng sut ng c, khbnh hng ca trng lng cp treo, trong thang

my sdng cp cn bng v i trng. Trng lng ca i trng thang

my chkhch thng chn:

Gt= Gbt+ G [kg]

Trong : Gt- Khi lng i trng, [kg]

Gbt- Khi lng bung thang, [kg]

G - Khi lng hng, [kg]= (0,35 0,4 ) - Hscn bng.

Nhvy, khc vi tnh cht ti ca ccu nng htrn cu trc, m men

cn ca cabin thang my lun mang tnh ma st (do h thng rnh trt nh

hng chuyn ng ca cabin to ra). Khi cabin y ti v i ln th ng c

lm vic chng c(gc phn tI), minh ha trn hnh 1.2, khi cabin y

ti v i xung th ng clm vic chng cvi chiu quay ngc li

(gc phn tIII).

Khi nng v hcabin khng ti, tnh hnh c khc, nng cabin khng ti

thc cht l hi trng xung, ng clm vic chng c(gc phn

t thIII) v hcabin khng ti thc cht l nng i trng ln, ng c lm

vic chng c(gc phn tthI)

Khi gim tc tcao xung thp nng cao cp chnh xc dng cabin,

ty theo chiu quay ng cslm vic chhm ti sinh (gc phn tth

II v IV)

Minh ha trn hnh vsau:

A1: nng cabin y ti tc cao

A2: nng cabin y ti tc thp (chun bdng khi n sn tng)

A1: hcabin y ti tc cao


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A2: hcabin y ti tc thp (chun bdng khi n sn tng)

C1, C2: Hm khi gim tc tcao xung thp trong chnng.

C1, C2

: Hm khi gim tc tcao xung thp trong chh.

TCB

TCB TCB

M

TCB

n

A1:Nng y tiA2:Gim tc

khi nng y ti,Hlm vic trngthi ng c

CB tai DTG G G+ >

C1: Nng ti nhC2: Gim tc khi

nng ti nhHlm vic trngthi hm ti sinh

CB tai DTG G G+ 3,014 (kW)

1.4. KT LUNQua cc nh gi v phn tch trn y c th a ra nh hng v

phng n truyn ng ssdng cho thang my l: Bbin i tn sba pha -

ng cin khng ng b. Sbnh gi hny p ng tng i y

t0tlv tngt0

M (Nm)

t (s)0


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cc yu cu vkthut, vtit kim nng lng, vdng chnh xc cabin v an

ton vn hnh thang my.


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CHNG II

NGHIN CU HTHNG BIN TN BA PHA

- NG CKHNG NG BROTOR LNG SC

Nh phn tch chng 1, phng n truyn ng bin tn ba pha

ng ckhng ng brotor lng sc sdng cho thang my hin nay l rt

ph hp. Trong thc t thng dung h thng bbin i tn s(dng chnh

lu PWM) - ng ckhng ng b(ASM Asynchronous Machine). Trong

chng 2, ta si nghin cu cthvhtruyn ng ny.

2.1. M hnh ton hc nhiu bin ca ng ckhng ng bba pha

Mun nng cao cht lng ca hthng iu tc bin tn - ng cxoay

chiu, ci thin phng php thit k, trc tin phi lm r bn cht trng thing ca ng cxoay chiu thng qua m hnh ton hc.

2.1.1. c im ca m hnh ton hc trng thi ng ca ng c

khng ng b

Khi nghin cu vng cin mt chiu ta nhn thy: T thng ca

ng cin loi ny c sinh ra bi cun dy kch t, c thc xc lp t

trc m khng tham gia vo qu trnh ng ca hthng (trkhi iu tc bng

iu chnh tthng). V vy m hnh ton hc trng thi ng ca n chc mt

bin vo ( l in p mch rotor) v mt bin ra ( l tc quay). Trong

i tng iu khin c cha hng sthi gian in cTmv hng sthi gian

in tmch in rotor Te, nu tnh cthit bchnh lu iu khin tiristor vo

th cn c chng sthi gian trca khi chnh lu. Trong ng dng k

thut, iu kin cho trc mt hscho php c thbiu din hthng tuyn

tnh cp III thnh hthng mt bin s(mt vo, mt ra), v hon ton c th

ng dng l thuyt iu khin tuyn tnh kinh in v phng php thit kk

thut thc dng v t pht trin ra tin hnh phn tch v thit k.

Tuy nhin, l lun v phng php ni trn khi vn dng vo vic phn

tch v thit khthng iu tc xoay chiu th gp kh nhiu kh khn, phi


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a ra mt sgithit mi c thnhn c scu trc trng thi ng gn

ng, bi v so snh gia m hnh ton hc ca ng cin xoay chiu v m

hnh ng cin mt chiu c skhc nhau kh cn bn:

(1) Lc iu tc bin tn ng ckhng ng bcn phi tin hnh iu

khin phi hp in p v tn s, c hai bin su vo c lp l in p v

tn s, nu kho st in p 3 pha th bin su vo thc t phi tng ln.

Trong bin su ra, ngoi tc quay, tthng cng c tnh l mt tham s

c lp. Bi v ng cchc mt ngun in 3 pha, vic xc lp tthng v

sthay i tc quay l tin hnh ng thi, nhng mun c cht lng ng

tt, cn mun iu khin i vi t thng, lm cho n khng thay i trong

trng thi ng, mi c thkhai thc c m men ln hn. V nhng nguynnhn ny nn ng ckhng ng bl mt hthng nhiu bin s(nhiu u

vo, nhiu u ra), m gia in p (dng in), tn s, tthng, tc quay li

c nh hng ln nhau, nn n l hthng nhiu bin c quan hvi nhau rt

cht ch. Trc khi tm ra m hnh ton hc r rng, c thdng shnh 2.1

biu din.

(2) Trong ng ckhng ng b, tthng ko theo dng in sinh ra m

men quay, tc quay ko theo t thng nhn c sc in ng cm ng

quay, bi v chng ng thi bin i, nn trong m hnh ton hc c cha hai

bin nhn vi nhau, nhvy, d khng kho st nhn tbo ho t, m m hnh

ton hc cng l phi tuyn.


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(3) Mch stator ng c khng ng b c 3 nhm cun dy, mi mt

nhm khi sn sinh tthng u c qun tnh in tring ca n, li thm vo

qun tnh cin ca hthng chuyn ng, v thd cho khng xt ti yu t

chm sau trong thit bbin tn, th m hnh ton hc ng ckhng ng bt

nht cng l hthng bc 7.

Tm li, m hnh ton hc ng ckhng ng bl hthng nhiu bin,

bc cao, phi tuyn, rng buc nhau rt cht, h thng iu tc bin tn ly n

lm i tng c thc thhin bng hthng nhiu bin nhtrn hnh 2.2.

2.1.2. M hnh ton hc nhiu bin ca ng cKB ba pha

Khi nghin cu m hnh ton hc nhiu bin ca ng ckhng ng b,

thng phi a ra mt sgithit nhsau:

(1) Bqua sng hi khng gian, coi 3 cun dy 3 pha i xng nhau (v

khng gian chng cch nhau 1200, sc in ng c sinh ra phn btheo quy

lut hnh sin dc theo khe hxung quanh;

(2) Bqua bo ho mch t, tcm v hcm ca cc cun dy u l

tuyn tnh;

(3) Bqua tn hao trong li st t; khng xt ti nh hng ca tn sv

thay i ca nhit i vi in trcun dy. D cho rotor ng cl loi dy

qun hay lng sc u chuyn i vrotor dy qun ng tr, ng thi chuyn

i v pha mch stator, s vng qun mi pha sau khi chuyn i u bng

nhau, nhvy, nhm cun dy ca ng cthc tc ng trthnh m hnh


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vt l ng ckhng ng b3 pha nhtrn hnh 2.3. Trong hnh, trc ca cc

cun dy 3 pha A, B, C trn stator l cnh, ly trc A lm trc ta chun,

ng trc ca cc cun dy trn rotor a, b, c l quay theo rotor, ng trc a

ca rotor lm vi ng trc A ca stator mt gc , gc in ny chnh l

lng bin thin gc pha khng gian. ng thi quy nh chiu dng ca in

p, dng in, tthng (tthng mc vng) ph hp vi thng lca ng c

in v quy tc bn tay phi. Lc ny, m hnh ton hc ca ng ckhng

ng bc hnh thnh bi cc phng trnh in p, t thng, m men v

phng trnh chuyn ng.

2.1.2.1. Phng trnh in p

Phng trnh cn bng in p ca nhm cun dy mch stator 3 pha l:

AA A 1

BB B 1

CC C 1

du i R

dt

du i R

dt

du i R

dt

= +

= +

= +


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tng ng vi n, phng trnh i xng in p ca nhm cun dy mch

rotor 3 pha sau khi tnh chuyn i vmch stator l:

aa a 2

bb b 2

cc c 2

du i Rdt

du i R

dt

du i R

dt

= +

= +

= +

trong : uA, uB, uC, ua, ub, ucl gi trtc thi ca in p pha stator v rotor;

iA, iB, iC, ia, ib, icl gi trtc thi ca dng in pha stator v rotor;

A, B, C, a, b, c l tthng ca cc cun dy cc pha;

R1, R2 l in trcun dy mt pha stator v rotor.

Cc i lng trn u tnh i vmch stator, n gin, cc k hiu

gc trn ca cc i lng sau khi quy i u lc bi, v di y

cng snhvy.

Phng trnh in p c vit dng ma trn, ng thi dng ton tp

thay cho k hiu vi phn d/dt:

A A A1

B B B1

C C C1

a a a2

b b b2

c c c2

u iR 0 0 0 0 0

u i0 R 0 0 0 0

u i0 0 R 0 0 0p

u i0 0 0 R 0 0

u i0 0 0 0 R 0

u i0 0 0 0 0 R

= +

(2.1)

hoc vit thnh:

u = Ri + p (2.1a)

2.1.2.2. Phng trnh tthng


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Tthng ca mi nhm cun dy u l tng ca tthng tcm ca bn

thn n v tthng hcm ca cc nhm cun dy khc i vi n, v vy t

thng ca 6 cun dy c biu din bng phng trnh ma trn sau:

A AA AB AC Aa Ab Ac A

B BA BB BC Ba Bb Bc B

C CA CB CC Ca Cb Cc C

a aA aB aC aa ab ac a

b bA bB bC ba bb bc b

c cA cB cC ca cb cc c

L L L L L L iL L L L L L i

L L L L L L i

L L L L L L i

L L L L L L i

L L L L L L i

=

(2.2)

hoc vit thnh:

= Li (2.2a)

trong L l ma trn in cm 6 6, vi cc phn ttrn ng cho chnh

LAA, LBB, LCC, Laa, Lbb, Lccl tcm ca cc cun dy stator v rotor ba pha, cc

phn tkhc cn li l hcm gia cc cun dy.

Trn thc t, t thng mc vng gia cc cun dy ca ng c c hai

loi: mt loi l t thng tn (r) ch lin quan n mt cun dy no ch

khng xuyn qua khe h, cn mt nhm na l tthng hcm xuyn qua khe

hgia chng, m loi sau l chyu. in cm tng ng vi tthng tn cacc pha ca mch stator c gi l in cm tn stator Lt1, do cc pha c tnh

i xng, gi trin cm tn ca cc pha l bng nhau; tng t, tthng tn

ca cc pha mch rotor tng ng vi in cm tn mch rotorLt2, tthng h

cm cc i mc vng gia cc cun dy trn mt pha ca stator tng ng vi

hcm stator Lm1, tthng hcm cc i mc vng gia cc cun dy trn

mt pha ca rotor tng ng vi hcm rotor Lm2, do sau khi tnh quy i s

vng qun trn nhm cun dy stator v rotor l bng nhau, v tthng hcm

gia cc cun dy u i qua khe h, t trbng nhau, nn c thcoi Lm1=

Lm2.


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46

i vi cun dy trn mi mt pha m ni, tthng m n mc vng l

tng ca tthng hcm v tthng tn, v vy, tcm ca cc pha trn mch

stator l:

LAA= LBB= LCC= Lm1+ Lt1 (2.3)

tcm ca cc pha trn mch rotor l:

Laa= Lbb= Lcc= Lm1+ Lt2 (2.4)

Gia hai cun dy khc nhau ch c h cm. Hcm li phn thnh hai

loi:

(1) Hcm gia 3 pha ca stator v hcm gia 3 pha ca rotor u l c

nh, nn hcm ny l hng s;

(2) Hcm gia mt pha bt kca stator vi mt pha bt kca rotor l

thay i, hcm l hm sca chuyn vgc .

Trc tin nghin cu loi thnht, bi v chnh lch gc pha gia ng

trc cun dy ca 3 pha l 1200, vi iu kin githit tthng phn bhnh

sin, trshcm l:

Lm1cos1200= Lm1cos(-120

0) = m1

1L

2 ;

Do :

LAB= LBC= LCA= LBA= LCB= LAC= m11

L2

(2.5)

Lab= Lbc= Lca= Lba= Lcb= Lac= m11

L2

(2.6)

Ring vloi thhai hcm gia cc cun dy trn stator v trn rotor, do

skhc nhau gia vtr cc pha (xem hnh 8.41), nn ln lt l:

LAa= LaA= LbB= LBb= LCc= LcC= Lm1cos (2.7)

LAb= LbA= LBc= LCb= LCa= LAc= Lm1cos(+ 1200) (2.8)

LAc= LcA= LBa= LaB= LbC= LCb= Lm1cos(- 1200) (2.9)


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Khi ng trc cc cun dy hai pha ca rotor v stator trng nhau, trs

hcm gia chng l ln nht, v lLm1.

em cc biu thc (2.3), (2.4), (2.5), (2.6), (2.7), (2.8), (2.9) thay vo biu

thc (2.2) sc phng trnh t thng hon chnh, r rng l phng trnh

ma trn ny rt s. n gin ngn gn, c thvit n di dng ma trn

khi:

ss srs s

rs rrr r

L L i

L L i

=

(2.10)

trong : s= [ABC]T,

r= [abc]T,

is= [iAiBiB]T,

ir= [iaibic]T,

m1 t1 m1 m1

ss m1 m1 t1 m1

m1 m1 m1 t1

1 1L L L L

2 2

1 1L L L L L

2 2

1 1L L L L

2 2

+

= + +

(2.11)

m1 t2 m1 m1

rr m1 m1 t2 m1

m1 m1 m1 t2

1 1L L L L

2 2

1 1L L L L L

2 2

1 1L L L L

2 2

+

= + +

(2.12)

0 0

T 0 0rs sr m1

0 0

cos cos( 120 ) cos( 120 )

L L L cos( 120 ) cos cos( 120 )

cos( 120 ) cos( 120 ) cos

+

= = + +

(2.13)

iu cn ch l, hai ma trn khiLrsvLsrc thi chcho nhau, v

lin quan ti v tr ca rotor, phn tca chng l bin s, l mt trong

nhng nguyn nhn lm cho hthng phi tuyn. lm cho tham strthnh


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hng scn phi dng php bin i ta , vn ny sc nghin cu chi

tit phn sau.

Nu thay phng trnh t thng (tc l phng trnh 2.2a) vo phng

trnh in p (2.1a), snhn c phng trnh sau khai trin:

di dLu Ri p(Li) Ri L i

dt dt

di dL Ri L i

dt d

= + = = +

= + +

(2.14)

Trong shngdi

Ldt

l sc in ng p mch trong sc in ng cm

ng in t(hoc sc in ng bin p), shng

dLi

d

l sc in ng quay

trong sc in ng cm ng in t, n tlthun vi tc gc .

2.1.2.3. Phng trnh chuyn ng

Trong trng hp tng qut, phng trnh chuyn ng ca h thng

truyn ng in c dng:

t cp p p

J d D KM M

n dt n n

= + + + (2.15)

Trong : Mcl m men phti (m men cn);

J l m men qun tnh ca htruyn ng;

D l hscn m men cn tlvi tc quay;

K l hsn hi m men quay;

np l si cc.

i vi phti m men khng i, D = 0, K = 0, th:

t cp

J dM M

n dt

= + (2.16)

2.1.2.4. Phng trnh m men

Da vo nguyn l bin i nng lng in c, trong ng cnhiu cun

dy, nng lng in ttrong ng cl :


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49

T T

m

1 1W i i Li

2 2= = (2.17)

Cn m men in t bng o hm ring i vi chuyn v gc m ca

nng lng in ttrong ng c, khi dng in khng i chc mt bin l

chuyn vgc mthay i, v m= /np, v vy :

m mt p

i constm i const

W WM n

==

= =

(2.18)

Ly cng thc (2.17) thay vo (2.18), ng thi xt ti quan hca cng

thc (2.11) (2.12) trong ma trn con ca in cm:

srT T

t p p

rs

0 L1 L 1M n i i n i i

2 2L 0

= =

(2.19)

Li bi v iT= [isT ir

T] = [iA iB iB ia ib ic], ly biu thc (2.13) thay vo

biu thc (2.19) ri khai trin ta c:

T Trs srt p r s s r

0

p m1 A a B b C c A b B c C a

0

A c B a C b

L L1M n i i i i

2

n L [(i i i i i i ) sin (i i i i i i )sin( 120 )

(i i i i i i )sin( 120 )]

= +

= + + + + + + +

+ +

(2.20)

Cn phi chra rng, cc cng thc trn u l tuyn tnh v nhn c

iu kin githit ttrng phn bu trn mch tv c dng hnh sin trong

khng gian, nhng thca dng in mch stator v rotor th khng chu bt

ciu kin githit rng buc no, chng c thl tu. Cng thc ny cng

c thnhn c trc tip t cng thc c bn khi vt th dn in chu lc

trong ttrng.

2.1.2.5. M hnh ton hc ng ckhng ng bba pha


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Tp hp cc cng thc (2.14), (2.16) v (2.19) [hoc cng thc 2.20] vo

lm mt sc m hnh ton hc nhiu bin sca ng ckhng ng b3

pha khi chu ti m men khng i.

T

p c

p

di Lu Ri L idt

1 L J dn i i M

2 n dt

= + +

= +

(2.21)

v:d

dt

=

Hphng trnh trn cng c thvit thnh dng tiu chun ca phng

trnh trng thi phi tuyn:

1 1

TpT0

c

di LL (R )i L u

dt

nnd Li i M

dt 2J J

d

dt

= + +

=

=

(2.22)

2.2. Gii thiu viu khin tn sng ckhng ng b

i vi ng cin khng ng bth tn sl thng siu khin rt

quan trng. iu khin tn sl phng php iu khin kinh in, tuy n i

hi kthut cao v phc tp v xut pht tbn cht v nguyn l lm vic ca

ng cl phn cm v phn ng khng tch bit.

Mt syu cu cht lng iu chnh nng cao th cc phng php kinh

in kh p ng c. Khi , phi sdng cc phng php iu khin ch

yu sau:

1. iu khin v hng (SFC: Scalar Frequency Control).

2. iu khin nh hng theo ttrng (FOC: Field Oriented Control)

3. iu khin trc tip momen (DTC: Direct Toque Control)


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2.2.1. iu khin v hng (SFC: Scalar Frequency Control)

Thc cht ca phng php iu khin v hng (U/f bng hng s) l

gicho tthng stator (s) khng i trong sut qu trnh iu chnh. Khi iu

khin tn s, nu gitthng khe hkhng i th ng csc sdnghiu qunht, tc l c khnng sinh mmen ln nht. Do nhng u im sn

c ca cc ng ckhng ng bm cc htruyn ng ca chng cng tha

hng tnh kinh tv tnh chc chn.

Phng php ny dthc hin tuy vy vn cn tn ti nhc im: tn

tht cng sut P v lng tiu thcng sut phn khng Q khng phi l nh

nht, n nh tc gp kh khn, mc d htruyn ng n gin nhng c

hn chvchnh xc tc v p ng mmen km. Htruyn ng khng

thm bo iu khin c cc p ng vmmen v tthng. Cho nn, iu

khin v hng c ng dng trong cng nghip khi yu cu khng cao v

iu chnh su tc .

Hnh 2.4: Cu trc iu khin v hng htruynng bin tnng ckhng ng b

A

CL

NL

C

TS

XL

TH

t tn sra NL

BD

f

ia

ib

UCA

Udc

DriverNL

PWM

-I

Sa,Sb,Sc

B C

TG

SI

ASM


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Cu trc cbn ca htruyn ng theo phng php iu khin v hng

c biu din trn hnh 2.4. Scu trc gm hai phn:

Phn lc gm: CL l khi chnh lu dng bin i in p xoay chiu

ca mng in cng nghip thnh in p mt chiu cp cho khi nghch lu;

NL l khi nghch lu thng dng cc kho ng ct IGBT, thc hin bin i

in p mt chiu Udcu ra khi CL thnh in p xoay chiu cung cp cho

ng c; C l ng ckhng ng bba pha rotor lng sc; C l tlc.

Phn iu khin gm: Khu to tn hiu khng chnghch lu theo nguyn

l iu chnh rng xung (Driver NL PWM); biu chnh bin in p ra

nghch lu (CA); cc sensor o dng (SI) v o tc (TG); khu bin i

dng ba pha ca ng c thnh in p mt chiu t l vi gi tr hiu dngdng in mt pha (BD); XL l khu gia cng tn hiu dng in v tc

ng cphc vcho mc ch n nh ng hthng; tn hiu t tc ca h

(TH) c a n khi t tn squyt nh tn sra ca NL, ng thi

THli c tng hp vi tn hiu u ra ca XL khng chbin in p

ra ca bin tn; cc tn hiu Sa, Sb, Scl cc chui xung dng khng chcc

kho IGBT trong ba pha ca nghch lu. Vic khng chqui lut thay i tn s

giai on khi ng do TS quyt nh, cn vic iu chnh in p c thc

hin bi CA.

2.2.2. iu khin nh hng theo ttrng (FOC: Field Oriented

Control)

iu khin nh hng theo ttrng cn gi l iu khin vect, c th

p ng cc yu cu iu chnh trong chtnh v ng. Nguyn l iu khin

vectda trn tng iu khin vectng ckhng ng btng tnh

iu khin ng c mt chiu. Phng php ny p ng c yu cu iu

chnh ca h thng trong qu trnh qu cng nhcht lng iu khin ti

u mmen. Vic iu khin vectda trn nh hng vect tthng rto c

thcho php iu khin tch ri hai thnh phn dng stator, t c thiu

khin c lp t thng v mmen ng c. Knh iu khin mmen thng


55/78

53

gm mt mch vng iu chnh tc v mt mch vng iu chnh thnh phn

dng in sinh mmen. Knh iu khin tthng thng gm mt mch vng

iu chnh dng in sinh tthng. Do hthng truyn ng in ng c

khng ng bc thto c cc c tnh tnh v ng cao, so snh c vi

ng cmt chiu.

Tm hnh ton hc ng ckhng ng bl mt hthng nhiu bin,

bc cao, phi tuyn, nhiu rng buc cht ch, thng qua php bin i ta , c

th lm n hbc ng thi n gin ho, nhng vn cha thay i bn cht

tnh phi tuyn v nhiu bin sca n. Cht lng ng ca hthng iu tc

bin tn khng c nhmong mun, tham sca biu chnh rt kh thit

kchnh xc, vn chnh l ch i theo khi nim h thng iu khinmt bin sm cha xt ti bn cht phi tuyn, nhiu bin s. Vvn ny

nhiu nh chuyn mn dy cng nghin cu, n nm 1971 c 2 cng

trnh nghin cu: Nguyn l iu khin nh hng ttrng ng ckhng

ng b do F. Blaschke ca hng Seamens Cng ho Lin bang c thc hin,

v iu khin bin i ta in p stator ng c cm ng do P.C.

Custman v A.A. Clark Mt c kt qu tt, v c cng btrong

sng chpht minh ca h. Tri qua nhiu ci tin lin tc hnh thnh c

h thng iu tc bin tn iu khin vector m ngy nay tr nn rt ph

bin.

Da quy tc ca php chuyn i l to ra sc in ng quay ng b,

dng in xoay chiu mch stator iA, iB, iCqua php bin i 3/2, c thchuyn

i tng tng thnh dng in xoay chiu ta cnh 2 pha i1, i1; sau

li thng qua php bin i quay theo nh hng t trng rotor, c th

chuyn i tng ng thnh dng in mt chiu iM1, iT1trn hta quay

ng b.


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Nu ngi quan st ng trn li st tv cng quay vi h ta , th

ngi quan st sthy nhl mt ng cmt chiu, tng tthng 2ca

rotor ng c xoay chiu ban u chnh l t thng ng cin mt chiu

tng ng. Cun dy M tng ng vi cun dy kch tca ng cmt

chiu, iM1(hay id1) tng ng vi dng in kch t, cun dy T tng ng

vi cun dy phn ng gi cnh, iT1 (hay iq1) tng ng vi dng in

phn ng v tlthun vi m men.

Tquan h tng ng trn y c thm t dng s cu trc ca

ng cnhtrn hnh 2.5. Vtng thm ni, u vo 3 pha A, B, C, u ra

tc gc , l mt ng ckhng ng b, qua php bin i 3/2 v bin i

quay ng btrthnh mt ng cmt chiu u vo iM1, iT1v u ra .

ng ckhng ng bqua bin i ta c thtrthnh ng cmt

chiu tng ng, nhvy phng theo phng php iu khin ng cmt

chiu, tm ra lng iu khin ca ng cmt chiu, qua php bin i ngc

ta tng ng, li c th iu khin ng c khng ng b. Bi v i

tng phi tin hnh bin i ta l vector khng gian (c c trng bng

sc tng) ca dng in, cho nn thng qua hthng iu khin thc hin

chuyn i ta c gi l h thng iu khin chuyn i vector

(Transvector Control System), gi tt l h thng iu khin vector (Vector

Control System), tng ca s nhtrn hnh 2.6.

Hnh 2.5. Scu trc bin i ta ng ckhng ng b.Trong : 3/2: Bin i 3 pha thnh 2 pha; VR: Bin i quay

ng b; : Gc gia trc M v trc (Trc A)


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Trong tn hiu cho trc v tn hiu phn hi i qua b iu khin

tng tnhhthng iu tc mt chiu dng, tn hiu t dng in kch

t*

M1i v tn hiu t dng in mch rotor*

T1i , i qua bchuyn i quay VR-

1, nhn c

* *

1 1i , i , tip tc i qua php chuyn i 2 pha/3 pha nhn c

* * *

A1 B1 C1i , i , i . Sdng ba dng in ny iu khin cng vi tn hiu iu khin

tn s1nhn c tbiu khin khng chbbin tn iu khin dng

in, to ra dng in bin tn 3 pha m ng ciu tc yu cu.

Khi thit kh thng iu khin vector, c thcho rng bchuyn i

quay ngc VR-1 a vo pha sau biu khin v khu chuyn i quay VR

trong bn thn ng ctrit tiu nhau, bchuyn i 2/3 v bchuyn i 3/2

pha trong ng ctrit tiu nhau, nu tip tc bqua trdo bbin tn sinh ra,

phn nt t trong khung trn hnh 2.6 c thbi hon ton, phn cn li rt

ging vi hthng iu tc mt chiu. C thtng tng rng, tnh nng trng

thi tnh v ng ca h thng iu tc bin tn xoay chiu iu khin vector

hon ton tng ng vi hthng iu tc mt chiu.i vi cc h truyn ng bin tn - ng cxoay chiu th cu trc

iu khin vector ta theo tthng rotor l mt trong nhng cu trc iu khin

hin i nht. Cu trc ca htruyn ng nhhnh 2.7. Trong shnh 2.7,

Hnh 2.6. tng cu trc hthng iu khin vect


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phn lc gm c ng ckhng ng bba pha rotor lng sc (ASM) v b

nghch lu (NL).

Phn iu khin gm cc khi chyu: cc sensor o dng 2 pha ng c

isav isb, my o tc quay ca ng c; khu chuyn i dng 3 pha thnh 2

pha tng ng is, is; khu bin i to - d-q i vi dng in

(CTi) v khu bin i tod-q-i vi in p (CTu); khu MHD

dng tnh gc lch gia vc ttthng rotor vi trc chun (gc e); khuiu chnh dng (CD) dng tnh cc thnh phn theo trc d v q ca in p

cn i vi cho ng c(usdv usq); khu iu chvector khng gian dng

tnh thi gian lm vic ca cc kho IGBT ca khi nghch lu (ta, tb, tc); *l

Hnh 2.7 : Cu trc iu khin vectca htruyn ngbin tn n cn b kch t nam chm vnh cu

32

iS

iS

iSd

iSqMHD

i*Sq

CD

CTU

CTi

3

NL

U

ASM

FT

uS

uS

uSd

uSq Se

Se

S

iSd

uc

CVTKG

a b c

iSa

iSc

+-


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gi trt ca tc gc; *sdi l gi trt thnh phn theo trc d ca dng in,

y l thnh phn to ra tthng rotor v y c chn bng hng s.

thc hin tng trn y sphi gii quyt nhiu vn phc tp.

Trc tin l, iu khin tn sv iu khin dng in trng thi ng sphi hp vi nhau nh thno? Vn ny cha hxut hin trong hthng

iu tc mt chiu, m trong hthng iu tc xoay chiu cn phi quan tm

gii quyt. Hai l, trong ng cmt chiu tthng lun l hng, cn trong h

thng iu tc bin tn iu khin vector th vn ny c duy tr ra sao?

2.2.3. iu khin trc tip momen (DTC: Direct Toque Control)

iu khin trc tip momen cho ng c khng ng b ba pha l

phng php iu khin trc tip ln momen in t, tc l i lng iu

khin gin tip.

Ni dung phng php da trn tc ng trc tip ca cc vectin p

ln vecttthng mc vng stator. Thay i trng thi ca vecttthng stator

dn n thay i trc tip ti momen in tca ng c. Cc vec tin p

c chn la da trn sai lch ca tthng stator v momen in tvi cc

gi trt. Tu thuc vo trng thi sai lch ca t thng v m men in t,

mt vectin p ti u nh trc c chn iu chnh i lng v

ng vi lng t. y l phng php iu khin n gin, t phthuc vo

cc thng sng c, p ng momen nhanh, linh hot.

Trong htruyn ng in bin tn - ng ckhng ng brotor lng sc

cho thang my la chn sdng phng php iu khin trc tip momen ng

ckhng ng bvi skhi nhtrn hnh 2.8.

Nhvy, u im ca phng php ny l chquan tm n cc vectilng stato m khng cn xc nh vtr ca roto nn n gin, t phthuc vo

cc thng sca ng c, p ng momen nhanh, linh hot. Nhc im ca

phng php l do biu chnh tthng l ON/OFF hai hoc ba vtr dn n

cc xung momen ng cnn khi lm vic tc thp kh n nh.


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2.3. Kt lun

Vn s dng ng c khng ng b rotor lng sc, m ra trin

vng to ln cho vic ng dng ng cny vo cc phti mang tnh cht th

nng. Vkthut, hthng ny t cc chtiu cao khi iu chnh tc cng

nhcc yu cu an ton khi vn hnh. Vkinh t, mra trin vng tit kim

in nng bng cch gim tn tht nhhm ti sinh v hscng sut cosy1.

Hnh 2.8: Skhi hbin tn ng ckhng ng b,iu khin trc tip mmen.

CLPWM NLLL

C

3

pha

Udc

Scla,b,c SNla,b,c

K chnhlu PWM

K nghchlu

KNLKCL

FT

BD

ASM


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CHNG III

KHO ST CHT LNG HTHNG

BIN TN BA PHA NG CKHNG NG BCHO

CABIN THANG MY3.1. Phn tch htruyn ng bin tn ng ckhng ng bcho Cabin

thang my

3.1.1. Khi mch lc

Mch lc bao gm mt bin tn 4 gc phn t (Khi chnh lu CL to

in p cao mt chiu, khi nghch lu NL to in p ba pha xoay chiu vi

tn smong mun). Chnh lu tch cc PWM c khnng to ra in p mt

chiu u ra cao p ng c yu cu in p ngun ca bin tn trong h

thng truyn ng bin tn ng ckhng ng brotor lng sc, ngoi ra

n cn c mt su im khc nh: m bo trao i cng sut hai chiu gia

ngun v ti, cho php ng clm vic c chhm ti sinh; dng qua

li c dng rt gn hnh sin; c thiu khin hscng sut cos= 1.

Hnh 3.12 l snguyn l phn mch lc ca hthng truyn ng. S

gm bin cm ngun L; hai scu ba pha bng cc IGBT lm nhimvchnh lu (CLPWM) v nghch lu (NL); tin C va l phn tcbn

trong schnh lu PWM, va l phn tlc; ng cASM.

Hnh 3.12: Snguyn l phn lc truyn ng bin tn ng ckhng ng brotor lng sc

uLuL

ASM


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60

3.1.2. Khi iu khin

a. iu khin chnh lu PWM:

C nhiu phng php iu khin b chnh lu tch cc PWM, mi

phng php iu khin c nhng u nhc im ring. Cc phng php iu

khin khc nhau c skhc nhau vi lng iu khin cng nhcu trc c

thca hthng iu khin nhng u nhm t mc tiu chung l iu khin

v gin nh gi trin p mt chiu u ra theo gi trt, khng chhs

cng sut theo yu cu, m bo dng dng in li gn vi hnh sin v cho

php thc hin trao i cng sut hai chiu gia ti v ngun.

Vi mc tiu nghin cu cc c tnh ca htruyn ng dng ASM, m

n t ph thuc vo phng php iu khin chnh lu. Do vy, chcn chnmt trong cc phng php iu khin c gii thiu, y ta chn phng

php VOC.

Cu trc chi tit khi iu khin chnh lu PWM iu khin theo VOC

c biu din trn hnh 3.13. Cc khu chc nng cbn ca khi iu khin

chnh lu theo phng php VOC gm:

- Khu o dng in v c lng in p li: Thc hin o dng xoay

chiu u vo chnh lu (iLa, iLb), bin i dng in hba pha sang vector

khng gian trn h tocnh - (iL, iL) v tnh cc thnh phn vector

in p li trn hto-(uL, uL).

- Khu bin i -k-: Thc hin xc nh gc gia vector in p

li v trc ca hto-, y cng l gc gia trc d ca htoquay

d-q vi trc ca hai h tocnh -, phc vcho vic chuyn to

cc vector dng v p.


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61

- Khu bin i -d-q lm nhim vbin i htovector dng

in li, u ra nhn c cc thnh phn ca vector dng in li trn hto

quay d-q (iLd, iLq).

- Khu bin i d-q -lm nhim vbin i htovector in p

ti qui i, u ra nhn c cc thnh phn ca vector in p ti trn hto

-(us, us) dng iu khin khu iu chrng xung PWM.

- Khu iu ch rng xung PWM: Thc hin to cc xung iu khin

cc kho ng ct ca mch lc, khu hot ng theo nguyn l iu chvector

khng gian.

- Cc biu chnh dng v p c la chn l cc bPI, tn hiu t ca

cc biu chnh dng l*

di c ly tu ra biu chnh in p v* =qi 0

(c ly bng khng theo iu kin h s cng sut bng 1). Nh vy, trn

PI

d - q

*

Ldi

k

*

dcU

iLq

*

Lqi 0=

PIPI

d-q

-

-

Khu o dng vc lng in pli

Khu iu chrng xung PWM

iLd

SCLa,b,ciLa iLb

us us

cos UL

sinUL

iLd iLq

iLiL

usq usd

cosUL

sinUL

-uL uL

Hnh 3.13: Cu trc khi iu khin chnh lu PWM theo VOC

Udc

Udc


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62

thc t, hchc mt tn hiu iu khin chung cho bchnh lu l tn hiu t

in p mt chiu*

dcU .

b. iu khin nghch lu:

Trn hnh 3.14 gii thiu khi iu khin nghch lu bao gm biu

chnh tc quay (CTQ) theo lut tltch phn (PI), cc khu chuyn i

ta khng gian, khu tnh gc quay, cc biu chnh dng ba pha (RIa, RIb,

RIc), khi iu chrng xung PWM. c tn hiu dng in v tc phc

vcho iu khin ca h thng ta sdng cc sensor o dng xoay chiu hai

pha ca ng c v my o tc quay (encoder). Cc tn hiu vo ca h

thng iu khin nghch lu gm c: Tn hiu t dng trc d (i*d) v tn hiu

tc gc (*r). Tn hiu t dng trc d c chn theo iu kin t thng

rotor khng i (i*d= const) v tn hiu t dng trc q (i*q) c ly tu ra

biu chnh tc quay, c a n khu chuyn i ta d-q -,

tip sau l khu chuyn i -abc cho ta gi trcn ca dng in ba pha

vo ng ci*a, i*b, i

*c. Cc gi trcn ca dng in c so snh vi gi tr

thc ca dng ng c, sau khi xl bi cc biu chnh dng v sau c

dng iu khin khi iu chrng xung PWM, to cc xung iu khinph hp khng chcc kha ng ct mch lc.

Thut ton iu khin chnh lu PWM theo VOC, thut ton iu khin

vector phn nghch lu u c xy dng bng cc phn mm. Cc phn mm

c thc vit bng mt sngn nglp trnh khc nhau nhbng ngn ng

C hoc bng Matlab.

- Vit chng trnh bng ngn nglp trnh C: Mt sthut ton iu khin

ca h truyn ng nh chng trnh tnh ton thi gian ng ct cc van

ca phn chnh lu PWM v phn nghch lu cbn ging nhau (khu iu

chPWM) v c lp bng ngn nglp trnh C.


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63

- Vit chng trnh bng ngn ngMatlab: Ngoi chng trnh tnh ton

c vit bng ngn ngC, cc biu chnh trong phn iu khin chnh lu

PWM v nghch lu, cc khu bin i to, mt sthut ton tnh ton c

lp trnh bng Matlab-Simulink.

Hnh 3.14: Cu trc khi iu khin nghch lu ca htruyn ngbin tn ng ckhng ng b rotor lng sc

Khu tch

phn I

ia

ib

CTQ: PI

iuch

PWM

e

iaicib

=const

ej

2

3

RIb

RIc

RIa

ia

Xung

Kcc

van

*di

*

*ai*bi

*ci

*qi

mp

2p


66/78


67/78

65

3.3. Sm phng v cc kt qu

3.3.1. Sm phng hthng v sminh ha chi tit:

Trong hthng ny sdng iu khin chnh lu PWM l phng php

VOC, cn phn nghch lu sdng phng php iu khin trc tip m men

(DTC). S m phng ton h thng dng phn mm PLECS chy trong

MATLAB, c biu din trn hnh 3-15, v cc sbiu din cc khi trong

hnh 3-15 c minh ha trn cc hnh vt3-16 n 3-25.

Hnh 3-15: Sm phng hbin tn 4Q -ng ckhng ng

bba pha rotor lng sc iu khin theo VOC - DTC

750

v_dc_ref

t1

t

i_vsi

100

i_ref

reactive

v_ref

v_dci_ref

Voltage

control

U/i_in

RRF->3ph

Phi

enable

m

v_dc

pulses

PWM

In1

In2

In3

Out1

Out2

Out3

Out4

Inv_motor

K-

Gain

In1Out1

Fan_model

Enable

control1

Enable

control

0

Display1

0

Display

m

i_ref

im

Current

control

pulses

s_abc

T_m

s_BC

i_vsi

i_s

m

v_dc

u_in

PLECS

Circuit

Circuit

3ph->RRF


68/78

66

pulses

a

b

c

+

-

phase

+

-

gate

phase

+

-

gate

phase

+

-

gate

phase

+

-

gate

g(u)

g(u): u>0

g(u)

g(u): u


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67

Hnh 3-18: Thng sng cASM


70/78

68

Hnh 3-19: M tton hc ng cASM

Tm

m

Llsa

Llsb

Llsc

Rsa

Rsb

Rsc

Lma

A

isa

A

isb

Lmb Lmc

Llra'

Llrb'

Llrc'

Rra'

Rrb'

Rrc'

A

ira'

A

irb'

vra'

vrb'

vrc'

ira

Vvrab

Vvrbc

irb

f(u)

sin(th)

f(u)

cos(th)

f(u)

cos(th-2/3*pi)

f(u)

cos(th+2/3*pi)

Airb'1

cos 0-+

vrab

vrbc

costh

vra'

vrb'

vrc'

vrabc'


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69

1

m

-C-

v_N

10

P

1

s

Integrator

1000

I

K*u

Decoupling

Enable

2

i

1

i_ref

Hnh 3-21: Khi Current Control

1

i_refSaturation

1

P

1

s

Integrator

20

I

Enable

2

v_dc

1

v_ref

Hnh 3-22: Khi Voltage Control


72/78

70

Hnh 3-23: Khi Inv_Motor

4

Out4

3

Out3

2

Out21

Out1

Step

delta_wT_ref

Speed Control

Mechanical

Magnetic

Electrical

T_ref

i_s

v_dc

s_abc

Direct Torque Control

m

Break Chopper Control

3 In3

2

In2

1

In1

Hnh 3-24: Khi Inv_Motor/ Direct Torque Control

1s_abcZ-Tab

Torque Control

f(u)

Torque

0.5866

Stator

Resistance

Phase Voltages

NOT

[2*4.02]

IC

Psi Sector(Psi)

Flux Sector

Flux Reference

Flux Control

1

s

Flux

0.5

f(u)

Abs

3

v_dc

2

i_s

1

T_ref


73/78

71

3.3.2. Cc kt qum phng

Thc hin m phng h thng vi gi thit ti t = 0 bt u cp ngun

xoay chiu vo bbin tn v kch hot shot ng ca chnh lu PWM. Ti t

= 1,25s tc ng gim tc t mt lng 10rad/s. Cc kt qu m phng

c biu din trn cc hnh 3-26, 3-27 v 3.28.

Hnh 3-25: Khi Inv_Motor/ Speed Control

1

T_refTorque

Limiter

Sum

Product

100

P

1

s

Integrator

1000

I

In1

In2Out

Anti Reset-Windup

1

delta_w

0 0.5 1 1.5 2 2.5 3-5

0

5

10

15

20

25

30

35

t(s)

n(m

ph)

Dac tinh toc do cua cabin thang may

Hnh 3-26.thtc ca Cabin


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72

Hnh 3-27.thm men ca Cabin

0 0.5 1 1.5 2 2.5 3-10

-8

-6

-4

-2

0

2

4

6

8

10

t(s)

momen

Dac tinh mo men cua cabin

m thuc

m dat

Hnh 3-28.thtc v m men ca Cabin

0 0.5 1 1.5 2 2.5 3

-80

-60

-40

-20

0

20

40

60

80

Dac tinh toc do va mo men cua cabin

t(s)

n

va

m


75/78

73

3.4. Kt lun:

Htruyn ng bin tn - ng ckhng ng brotor lng sc p

ng c yu cu cng ngh ca mt cabin thang my nh cao tng. V vy,

mc d gi thnh ca loi bin tn ny cao gp i so vi bin tn thng thng

nhng vi htruyn ng ny, c bit l khi ng dng vo cc hthng thang

my, my bm, qut gi, l rt ph hp.


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74

KT LUN V KIN NGH

Kt lun chung

Hin nay, i vi cc hthng truyn ng in hin i, ng ckhngng brotor lng sc ang c thay thdn ng cin mt chiu. iu c c l do ng dng bin tn iu khin vectl ngun cung cp cho ngcxoay chiu. iu ny dn n cht lng sn phm u ra, hiu qukinh tca mt hthng cng nghc ci thin r rt.

- Lun vn bc u tm hiu vbin tn v htruyn ng bin tnng ckhng ng brotor lng sc. Cth, nghin cu vbin tn tit kimnng lng c thlm vic c4 gc phn t, cho php hhm ti sinh.

- Lun vn hon thnh nhng yu cu t ra l tm ra c cc giiphp kh thi iu khin tc ng c khng ng brotor lng sc chocabin thang my theo gin tc yu cu.

- Cn cvo kt qum phng ta thy: Cht lng iu khin tt.

Kin ngh

Do thi gian c hn nn lun vn chdng li kt qum phng, tuynhin kt qum phng cng cho thy tnh ng n ca ti cn nghin cu.Cn rt nhiu vn lin quan cng nhtrong nhng qu trnh sdng cthcn c nghin cu v y cng l nn tng cho nhng ti tip theo tngbc khai thc v thc hin. V dnh:

- Hm ti sinh trnng lng vli khi sdng bin tn 4Q- Cc phng php iu khin vectkhi sdng ng cxoay chiu,....

------------------------------o0o------------------------------


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75

TI LIU THAM KHO

Ting Vit

1. Trn Khnh H (1997),My in tp 1, Nh xut bn Khoa hc v kthut, H Ni.

2. Bi Quc Khnh, NguynVn Lin, Phm Quc Hi, Dng Vn Nghi (2002), T

ng iu chnh truyn ng in, Nh xut bn Khoa hc v kthut, H Ni.

3. VGia Hanh, Phan TTh(1992- Bin dch),My in, Nh xut bn Khoa hc v

kthut, H Ni.

4. Bi Quc Khnh, Nguyn Vn Lin (2007), C s truyn ng in, Nh xut bn

khoa hc v kthut, H Ni.

5. Nguyn Phng Quang (1996), iu khin tng truyn ng in xoay chiu ba

pha, Nh xut bn Gio dc, H Ni.6. Nguyn Phng Quang, (2003) MATLAB & Simulink dnh cho k siu khin t

ng, Nh xut bn Khoa hc v kthut, H Ni.

7 Bi Quc Khnh, ng Hng Hi, on Vn Tun (2010), iu bin vecto khng

gian cho bin tn ma trn gin tip 3 pha -4 dy, Tp ch Khoa hc Cng

nghHng hi s22 04/2010

8 Bi Quc Khnh, ng Hng Hi, on Vn Tun (2010), Thit kchuyn mch cho

bin tn ma trn trc tip 3 pha 4 dy, Tp ch Khoa hc Cng nghHng

hi s24 11/2010

Ting Anh

9 A. S. Mostafa, A. L. Mohamadein, E. M. Rashad (1993), Analysis of series-

connected wound-rotor self-excited induction generater, IEEE

PROCEEDINGS-B, 140 (5), 329-335.

10 Adel L. Mohamadein, Yasser G. Dessouky, Mohmoud S. Abouzid (2000), Theory

and Performance of Series Connected Synchronous Motors,IEEE.

11 C. Daoshen and B. K. Bose (1992), Expert system based automated selection of

industrial AC drives,IEE IAS Annu. Meet. Conf. Rec., pp 387-392.

12. S. M. Chhaya and B. K. Bose (1992), Expert system based automated designtechnique of a voltage-fed inverter for induction motor drive, IEE IAS Annu.

Meet. Conf. Rec., pp 770-778.

13. S. M. Chhaya and B. K. Bose (1995), Expert system aided automated design,

simulation and controller tuning of ac drive system, IEE IECON Conf. Rec.,

pp 712-718.

14. Essam E. M. Rashad, Mostafa E. Abdel Karim (1996), Yasser G. Dessouky, Theory


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and Analysis of Three-phase Series-connected Parametric Motors, IEEE

Transaction on Energy Conversion, Vol 11 (4), pp715-720.

15. dSPACE (2004), dSPACE 1103 User manual version 4.1

16. K. H. Bayer, H. Waldmann and M. Weibelzahl (1972), Fiel-oriented close loop

control of a synchronous machine with the new transvector control system,

Siemens Review, vol. 39, pp 220-223.

17. Mariusz Malinowski (2001), Sensorless Control Strategies for Three Phase PWM

Rectifiers, Warsaw, Poland.

18 P. Barrass, M. Cade (1999), PWM rectifier using indirect voltage sensing, Proc.IEE-

Elect. Power Applicat., 146 (5), 539-544.

19. Plexim GmbH, PLECS - Piece-wise Linear Electrical Circuit Simulation for

Simulink, User Manual, ver 1.2.

20. The Mathworks, Simulink-Dynamic System Simulation for Matlab, Help file in

Matlab7.01 R14.

bien tan 3pha tiet kiem nang luong

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