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1/7

Lun vn

ng cservo

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N TT NGHIP

- Cng thng c. H

dng qua p

nht khi g

vi vect d

= 0o vect

moment tr

t c gi

cho cun d

t trng c

mmen n

Hnh 1.

Servo D

Hnh 1.1: Cu to ng c Servo DMC

c (1) cho thy phn t sin nh hngnh 1.2 ch ra quan h gia vect t tr

n ng. moment trn trc ng c tng

c =90o c ngha l khi vect t trn

ng phn ng, moment trn trc ng c l

dng phn ng song song vi vect t t

trc l nh nht. m bo moment tr

tr ln nht cn thit phi iu khin c

y roto sao cho vect dng phn ng lu

nh. Vi cch iu khin qu trnh

g c s bin thin t l vi dng cp cho c

2: Vect t trng c nh vect dng

C

Trang 2

GVHD: PHM VN MNG

chi than

ti moment trn trcng c nh v vect

n t = 0o v ln

c nh vung gc

ln nht khi v khi

ng c nh, ti

n trc ng c lun

uyn mch cp in

lun vung gc vi

cp in nh trn,

un dy phn ng.

v momen ng c

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N TT NGHIP

- Mt m

quay c

trong cun

- Mmen

hai phng

- Trong

Iu

E

- Mch

- T nh

- Thnh p

phng trn

- Phng

V

lin h khc gia cc thng s ca n

rto t l vi sc in ng phn in

y phn ng

v tc ca ng c Servo DC iu khi

trnh sau: Tc= Km.Iu (

Eb=Kb. (3)

: Tc- l mmen t, Nm

- dng in trong cun dy phn ng, A

b- in p phn in (emf), V

m- h s mmen, kgm/A

b- h s in, n v o vn trn vng tr- vn tc quay ca ng c, vng/pht

ng c Servo DC ch ra trn hnh 1.3

nh 1.3: Mch ng c Servo DC

lut Kirchhoff ta c phng trnh mch

uu b u u u

dIV K . R .I L .(

dt

hn L nh hn so vi R nn c th b

s l:

V RI = Kb

trnh mmen ti Tm t trn trc ng c

Tm = T + Ts + Tc

Td =Jc (d/ dt)

Ts = fdc

Trang 3

GVHD: PHM VN MNG

c mt chiu l tc

ng phn in sinh ra

n c th m t bng

)

pht

) (4)

qua L. B qua L

(5)

:

(6)

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Trang 4

N TT NGHIP GVHD: PHM VN MNG

Tc =Jm (d/dt)+fm

- Trong :

T - mmen ng;

Ts

- mmen tnh;

Tc - mmen cn;

Jc- mmen qun tnh roto ng c;

Fc- h s sc cn nht ca ti;

Jm mmen qun tnh ti;

Fm- h s sc cn nht ca ti;

- ng c quay th mmen ng c phi bng vi mmen ti:

Tm= Tc=Km.Iu (7)- u im ca ng c Servo DC chi than l n gin trong iu

khin v gi thnh sn phm r. Tuy nhin s dng chuyn mch c kh

gy ra n, tng nhit trn vnh gp v qun tnh r to cao khi gim tc

. khc ph cc nhc im trn ngi ta s dng ng c Servo

DC khng chi than.

b. ng c Servo DC khng c chi than

- ng c Servo DC khng c chi than c s dng ph bin trong

my cng c iu khin s. Cu trc ca n v c bn ging nh ng c

Servo DC chi than nhng khc ch cc cun pha ca ng c lp trn

Stato v Rto l nam chm vnh cu. Roto c ch to t vt liu ferit

hoc samari coban . Rto lm t vt liu samari coban c kh nng tp

trung t cao v t d thp. Nhng gi thnh rto loi ny cao hn nhiu

so vi khi rto lm t vt liu ferit. V vy, n ch dng ch to rtocho ng c cng sut ln. Tng t nh ng c xoay chiu, t trng

quay trong ng c DC khng chi than c sinh ra nh mch iu

khin th t cp dng cho cc cun pha. Cun dy pha ca ng c

khng chuyn ng v vy c th s dng chuyn mch bng in t nn

loi tr bng nhng nhc im tn ti trong ng c DC Servo chi

than.

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N TT NGHIP

4.4 M hnh sau khi thi cng

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GVHD: PHM VN MNG

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N TT NGHIP GVHD: PHM VN MNG

DANH MC TI LIU THAM KHO

[1] Mitsubishi cc b iu khin lp trnh. S tay hng dn lp trnh cc b iu

khin h FX (Fxo, Fxos, FXon, FX, FX2c

[2] Proface-Operation Manual (this Manual), Vol 1

[3] Proface-Device/PLC Connection Manual, Vol 4

[3] Mitsubishi, General Purpose AC Servo, MELSERVO-C Series, Instruction

Manual.