1369991639_1369991639

Ti liu c ng trn website h ttp ://www.ta ilieuhoc.edu.vn

BO CO THC TP

ti:

My bin p v ng c


LI NI U

Hc i i vi hnh lun l phng chm hng u ca nn

gio dc nc ta. Do vic hc tp trong Nh trng c tnh thc

tin v i st vi nhu cu thc t ca x hi hn. th vic i thc tp

i vi mi sinh vin khi ang cn ngi trn gh Nh trng l rt cn

thit. Bi trong thc t x hi cho ta thy rng trong Nh trng th

chng ta mi ch c hc nhng kin thc ht sc c bn. mc d

chng ta c thc hnh trn my theo mi ngnh hc ca m nh.

Nhng cn v thc t x hi th sao? Mt cu hi t ra cho mi sinh

vin m buc chng ta phi c cu tr li vi nhng vn kin thc c

bn v x hi m chng ta c hc.

V vy vic i thc tp l c hi p dng nhng kin thc hc

c Nh trng vo thc t x hi. Khng nhng th thc tp cn

gip cho chng ta hc tp v nng cao kin thc cho m nh. ng thi

cng gip chng ta hiu r thm v cng vic v thc c tm qu

trnh ca cng vic vi ngnh mnh ang theo hc, vic i thc tp

c tt hn v pht trin hn na.

Bn cnh vic i thc tp cng rn luyn cho chng ta c mt

thc thc hin cc ni quy, quy nh ca Cng ty cng nh cc c

quan. ng thi buc chng ta phi chu trch nhim hon ton vi

nhng vic m nh v ang lm. gip em hon thnh tt bi bo

co thc tp nhn thc vi chuyn my bin p v ng c.

H Ni, 29 thng 08 nm 2010

Hc Sinh:

Lu Minh Thng


I. TM HIU V C S THC TP

Cng ty TNHH Hal Vit Nam l Cng ty c thnh lp nm

2005. qua 5 nm thnh lp Cng ty ngy cng pht trin vi nhiu mc

tiu khc nhau. Nm KCn Bc Thng Long ng Anh - HN vi mt

v tr ht sc thun li cho vic giao lu v kinh doanh vi cc Cng ty

khc. l mt Cng ty chuyn lp t h thng in, iu ho cho cc

cng trnh v vy i hi nhng kh nng lm vic rt tt. Khi c yu

cu t khch hng lp tc cc nhn vin k thut c ph bin nhim

v v bt tay vo cng vic ca m nh.

Ton b h thng iu hnh ca Cng ty c minh ho theo s

sau:

1. S B MY T CHC CA CNG TY TNHH HAL VIT

NAM

2. CHC NNG, NHIM V CC B PHN TRONG CNG TY

TNHH HAL VIT NAM

Gim c

Ph Gim c

Ph Gim c Trng phng k thut

Chuyn vin k thut

Nhn vin lp

t

Cng Nhn

SX

Th k

Ti v

K ton


1. Gim c: l ngi lnh o v iu hnh v mi mt hot

ng ca Cng ty c th nh sau:

- K kt cc hp ng thi cng vi cc i tc.

- K kt cc giy t vn bn trong Cng ty.

- T chc v iu hnh cc cuc hp ca ban lnh o Cng ty.

2. Ph Gim c: l ngi gip vic cho Gim c. Thay mt

Gim c iu hnh cc hot ng ca Cng ty khi Gim c i cng

tc. Thc hin gii quyt cng vic khi c Gim c u quyn.

Ch ng lp chng trnh cng tc, ch o cc cn b cng

nhn vin thuc phn ph trch lm vic theo ng quyn hn v

nhim v ca minh.

3. Trng phng k hoch: vch ra k hoch lm vic cho cc

phng ban trong Cng ty. Ch u trch nhim v cc hot ng ca cc

phng ban.

4. Trng phng k thut: chu trch nhim gim st v thit k

cc hng mc thi cng cc gi thu. Chu trch nhim chnh v phn k

thut thi cng, lp t.

5. K ton: l ngi chu trch nhim son tho cc giy t, vn

bn lin quan trong Cng ty. Trnh cc giy t cn k kt cho Gim

c. Xy dng k hoch thu chi hng thng.

6. Ti v: l ngi chu trch nhim qun l qu lng trong

Cng ty. K cc giy t thu chi ca Cng ty.

7. Nhn vin kho st thit k thi cng: chu trch nhim kho

st cng trnh cn thi cng lp t. V cc bn v thi cng lp t .

8. Chuyn vin k thut: Chu trch nhim gim st cc hot

ng thi cng lp t ca cc nhn vin k thut.

9. Nhn vin lp t: l nhng cng nhn k thut tay ngh cao

trc tip vn chuyn v lp t thit b.

3. NI QUY CA CNG TY C PHN XY LP V NG DNG

CNG NGH:


- Mi cn b cng nhn vin trong Cng ty phi chp hnh ng

theo quy nh m Cng ty ra.

- i lm ng gi.

+ Sng: t 7 gi n 11 gi.

+ Chiu: t 1 gi n 5 gi.

- Mi cn b cng nhn vin trong Cng ty phi nhit tnh trong

cng vic, lun phn u vi mc tiu uy tn v cht lng.

- Nhng phng ban, c nhn no c thnh tch tt s c khen

thng v tuyn dng.

- Mi c nhn u c ng bo him theo quy nh ca php

lut.

- Mi c nhn u c ngh l, ngh php hay ngh m theo quy

nh ca Nh nc.

- Cm mi c nhn lm vic ring, b vic t do trong gi lm

vic.

- Cm cc hnh vi sao chp, chm cp ti liu ca Cng ty. Nu

vi phm s b truy t trc php lut.

- Cm mi hnh vi chia b phi gy ri ni b trong Cng ty.

4. NHNG THUN LI, KH KHN CA CNG TY TNHH HAL

VIT NAM TRONG QU TRNH HNH THNH V PHT TRIN

1. Thun li:

Cng ty TNHH Hal Vit Nam ra i trong thi k th trng in

t v cc thit b in t pht trin mnh. Cng ty c nhng iu

kin v cng thun li gp phn vo s pht tr in ngy cng ln mnh

ca Cng ty.

Cng ty ra i trong hon cnh t nc ta ang trong thi k

pht trin cng nghip ho in i ho nn c rt nhiu cc nh my

x nghip mc ln cc trung c c xy dng cng nhiu, cc nh

hng, khch sn to cho Cng ty c nhiu n hng t Cng ty

tch lu c nhiu kinh nghim thc t trong lnh o v hot ng.


Bn cnh Cng ty cn c c mt thun li na l s c

gng, n lc ht sc m nh ca ton th cc cn b cng nhn vin trong

Cng ty gp phn xy dng Cng ty ngy cng vng mnh, to c

uy tn ln trn th trng.

2. Kh khn:

Trong nhng ngy u thnh lp i ng cn b, cng nhn k

thut tay ngh cao cn mng nn khng th trnh khi nhng b ng

ban u khi i vo hot ng.

Khi i vo hot ng Cng ty gp phi s cnh tranh khc li t

ca cc i th khc hn na cc trang thit b cn ngho cng lm

cho Cng ty c nhng hn ch nht nh.

Tuy nhin Cng ty tng bc khc phc c nhng hn ch

v i ng cn b k thut v trang thit b trong Cng ty.

Ti liu c ng trn website http://www.ta ilieuhoc.edu.vn

Sinh vin: Lu Minh Thng Lp: T08A 7

PHN I. L THUYT V CC BI TP K thut in l mt ngnh rt quan trng trong cuc sng

hin nay. Ngi ta ng dng n trong mi lnh vc ca cuc sng

nh. Bin i nng lng o lng, iu khin v x l tn hiu

Trong c bit quan trng i vi cc ngnh thit b in n

gip sn xut ra cc thit b ng dng trong sinh hot ca con

ngi. Trong cuc sng hin nay my in c s dng ht sc

rng ri c bit i vi Vit Nam khi ang trong thi k in kh

ho v t ng ha th vai tr ca n ngy cng tr nn quan

trng. Cc pht minh lin tc c ra i nhiu cng ngh mi

c s dng phc v rt c lc cho con ngi.

i vi ngnh h thng in, chuyn ti nng lng in l

mt cng vic ht sc quan trng vi s tr gip ca cc my in

c bit l cc my bin p. Chng ta thu c nhiu hiu qu

v mt kinh t cng nh bo v mng li in.

Cn trong lnh vc sn xut vi s ra i ca cc ng c

in lm tng c nng sut lao ng.

Chnh v nhng l do nh vy nn trong chng trnh thc

tp ca khoa in trng THBC Kinh t - K thut Bc Thng

Long a vo nhng bi tp thc t. Nhm gip sinh vin nhn

thc c k thut cng nh cc nguyn l hot ng ca cc

thit b. Em xin chn thnh cm n cc thy, c trong ban ch

nhim khoa cng cc thy hng dn trong qu trnh thc tp.



PHN II. C S L THUYT V MY IN I. KHI NIM CHUNG V MY IN

1 . S lc v my in

My in l mt sn phm ca k thut in. N l mt h

thng in t gm c cc mch t v mch in c lin quan vi

nhau. Mch t gm cc b phn dn t v khe h khng kh, cc

mch in gm hai hoc nhiu dy qun c th chuyn ng tng

i vi nhau cng vi cc b phn mang chng.

N hot ng da trn nguyn l cm ng in t. Nguyn l

ny cng t c s cho s lm vic ca b bin i in nng, vi

nhng gi tr ca thng s ny (in p, dng) thnh in nng

vi cc gi tr thng s khc. My bin p l mt b bin i cm

ng n gin thuc loi ny, dng bin i dng in xoay

chiu t in p ny thnh in p khc, cc dy qun v mch t

ca n ng yn v qu trnh bin i t trng sinh ra sc

in ng cm ng trong cc dy qun c thc hin bng

phng php in.

My in dng lm my bin i nng lng l mt phn t

quan trng nht i vi bt c thit b in nng no. N c s

dng rng ri trong nng nghip, giao thng vn ti, cc h iu

khin v t ng iu chnh, khng ch.

My in c nhiu loi:

- My ng yn: My bin p.

- My in quay: Tu theo tng loi li in c th chia

lm hai loi my in xoay chiu v my in 1 chiu.

- My in xoay chiu c th phn chia thnh:

+ My in ng b.

+ My in khng ng b.

+ My in xoay chiu c vnh gt.

2. S lc v vt liu ch to my in:



Vt liu ch to my in c chia ra lm ba loi l: vt

liu tc dng vt liu kt cu v vt l iu cch in.

a. Vt liu tc dng : ch to my in gm vt liu dn

in v vt liu dn t. Cc vt liu ny c s dng to iu

kin cn thit sinh ra cc bin i in t.

* Vt liu dn t: ch to mch t ca my in. Ngi

ta dng cc loi thp t tnh khc nhau nhng ch yu l thp k

thut in, c hm lng silic khc nhau nhng khng qu 4,5%.

Hm lng c th hn ch tn hao do t tr v tng in tr ca

thp gim tn hao dng in xoy.

i vi my bin p ngi ta thng s dng ch yu l cc

l thp dy 0,35, 027mm, cn cc my in quay th ch yu l

thp c dy 0,5mm chng c ghp li gim tn hao dng

in xoy gy nn.

Ngy nay ngi ta sn xut v chia ra lm hai loi thp k

thut in.

+ Cn nng.

+ Cn ngui.

- Loi cn ngui c nhng c tnh t tt hn nh t thm

cao tn hao thp t hn loi cn nng. Thp cn ngui li c

chia lm 2 loi: d hng v ng hng

b. Vt liu dn in.

Vt liu thng dng l ng. ng dng lm dy dn khng

c c tp cht qu 0,1%. in tr xut ca ng 200 l P =

0,0172 .mm2/m. Nhm cng c dng rng ri lm vt liu dn

in. in tr sut ca nhm 200c l P = 0,0282 .mm2/m,

ngha l gn gp hai ln in tr sut ca

Cp cch Y A E B F H C

in



Nhit 90 105 120 130 155 180 >180

Cho php

c. Vt liu kt cu

Vt liu kt cu dng ch to cc b phn v chi tit

truyn ng hoc kt cu ca my theo cc dng cn tht, m bo

cho my in lm vic b nh thng. Ngi ta thng dng: ngang,

thp, cc kim loi mu, hp kim v cc vt liu bng cht do.

* Vt liu cch in:

vt liu cch in i hi c bn cao, dn nhit tt, chu

m, chu c ho cht v bn c cao.

i vi cc vt cch in th nhit nh hng rt nhiu

n tui th ca chng v th khi chng ta s dng cn ht sc ch

v nhit ni lm vic ca cc thit b.

Trn y l mt s cch nhn s loc nht v my in cng

nh cc nguyn l chung nht ca my in ng thi cng xt

qua v cc vt liu s dng trong k thut in. Sau y chng ta

tm hiu v b my bin p v cc my in xoay chiu.

II. MY BIN P V NG C

1. My bin p

a. S lc chung v my bin p

My bin p l thit b rt quan trng trong qu trnh truyn

ti in nng cng nh trong sn xut. N ra i t nhu cu kinh

t ca vic truyn ti lm sao cho t hiu qu kinh t nht.



S mng truyn ti in n gin (h nh 2.1)

My pht in ng dy ti

H tiu th

Nh chng ta bit, cng mt loi cng sut truyn ti trn

ng dy, nu bin p c tng cao th dng in chy trn

ng dy nh i, do trng lng v chi ph dy dn gim

xung. Ngy nay c rt nhiu cc loi my bin p, my bin p

s dng trong o lng (cc loi my bin p c cng sut nh) v

my bin p c cng sut ln s dng trong truyn ti (35kw, 110

kw, 220kw 500kw) Trong h thng in lc, mun truyn ti v

phn phi cng sut t cc nh my n cc h tiu dng mt cch

hp l, thng phi qua ba, bn ln tng v gim in p. Hin

nay cc bin p c s dng chuyn dng hn, chng c dng

trong cc ngnh chuyn mn, nba chuyn dng cho cc l luyn

kim, my bin p hn in my bin p cho cc thit b chnh

lu khuynh hng hin nay ca my bin p. nc ta hin nay

ngnh ch to my bin p ra i ngay t ngy ho bnh lp li.

n nay chng ta sn xut c mt khi lng kh ln my

bin p, vi nhiu chng loi khc nhau phc v cho nhiu ngnh

sn xut trong nc v xut khu. Hin nay sn xut c

nhng nba dung lng 63.000kVA vi in p 110KV.

ng dy dn

My bin p tng p My bin p gim p

u ra



b. Nguyn l lm vic ca my bin p

Ta xt s nguyn l ca mt my bin p nh hnh v.

y l my bin p mt pha dng hai dy qun. Dy qun

mt c W1 vng dy v dy qun hai c W2 vng dy c qun

trn li thp 3. Khi t mt in p xoay chiu U1 vo dy qun

1, trong s c dng in i1. Trong li thp s sinh ra t thng

mc vng c 2 cun dy 1 v 2, cm ng ra sut in ng e1

v e2. Dy qun 2 c s.. s sinh ra dng in i2 a ra ti vi

mt in p U2. nh vy.

Nng lng ca dng in xoay chiu c truyn t dy

qun 1 sang dy qun 2.

Gi s in p xoay chiu t vo l mt hm s Sin th cc

thng s m n sinh ra cng l mt hm s Sin = m. Sin t.

Do theo nh lut cm ng in t s.. trong cc cun

dy s l:

e1 = -W1.d /dt = -W1.dm.Sin t/dt = -W1mcos t

=

Tng t ta c:

Vi e1 = 4,44 f1m

E2 = 4,44 f2m

L cc gi tr hiu dng ca cc s.. dy qun 1 v 2

UR

I2 I1

UV

)2/(12 tSine )2/(122 tSinee



Cc biu thc trn cho thy l s.. cm ng trong dy qun

chm pha vi t thng sinh ra n mt gc /2

Da vo cc biu thc ca e1 v e2 ngi ta nh ngha t s

bin i ca my bin p nh sau: k = e1/e2 = W1/W2

Nu khng k in p ri trn cc dy qun th c th coi l

U1 e1 v U2 e2 v do k c xem nh l t s gia dy

qun 1 v 2.

c. Cc loi my bin p chnh

1. My bin p in lc dng truyn ti v phn phi

cng sut trong h thng in lc.

2. My bin p chuyn dng dng cho cc l luyn kim, cc

thit b chnh lu v my bin p dng hn in

3. My bin p t ngu bin i in p trong khong in

p khng ln, dng m my cho cc ng c in xoay chiu.

4. My bin p o lng dng gim in p khi c dng

in ln chy qua ng h o.

5. My bin p th nghim dng th nghim cc in p

cao

d. Cu to my bin p

My bin p c cc b phn chnh sauy: li thp, dy qun

v v my.

My bin p kiu li mt pha (h nh 2.3a)

Ba pha (hnh 2.3b)

T thng

V 12

12



+ Li thp: dng lm mch dn t, ng thi chng lm

khung qun dy qun theo h nh dng ca li thp ngi ta chia

ra:

- My bin p theo kiu li hnh tr (hnh 2 3): dy qun

bao quanh tr thp. Loi ny hin nay rt thng dng cho cc my

bin p mt pha v ba pha c dung lng nh v trung bnh.

- My bin p kiu bc: mch t c phn nhnh ra 2 bn

v bc ly mt phn dy qun. Loi ny thng ch dng trong

mt vi ngnh chuyn mn c bit nh: my bin p dng trong

l luyn kim hay my bin p dng trong thut v tuyn in,

truyn thanhvv.

cc My bin p hin i, dung lng ln v cc ln (80

100 MVA trn mt pha), in p tht cao (220 4000KV),

gim chiu cao ca tr thp, tin li cho vic vn chuyn trn

ng, mch t ca my bin p kiu tr c phn nhnh sang

hai bn nn my bin p mang hnh dng va kiu tr, va kiu

bc, gi l my bin p kiu tr bc ba pha (trng hp ny c

dy qun ba pha, nhng c 5 tr thp nn cn gi l my bin p

ba pha nm tr).

Li thp my bin p gm 2 phn: phn tr k hiu bng

tr T v phn gong k hiu bng ch G (hnh 2 3). Tr l phn

My bin p kiu tr bc

Tr bc m t pha Tr bc ba pha



li thp c qun dy qun: gng l phn li thp ni cc tr l i

vi nhau thnh mch t kn v khng c dy qun. i vi my

bin p kiu bc (hnh 2 4) v kiu tr bc (hnh 2 5), hai tr

thp pha ngoi cng u thuc v gng. gim tn hao do dng

in xoy gy nn, li thp c ghp t nhng l thp k thut

in dy 0,35mm c ph sn cch in trn b mt. Tr v gng

c th ghp vi nhau bng phng php ghp ni hoc ghp xen

k. ghp ni th tr v gng ghp ring, sau dng x p v bu

lng vt cht li (hnh 2-6). ghp xen k th ton b li thp phi

ghp ng thi v cc lp l thp c xp xen k vi nhau ln

lt theo trnh t a, b nh h nh 2-7. sau khi ghp, li thp cng

c vt cht bng x p v bulng. phng php sau tuy phc tp

song gim c tn hao do dng in gy nn v rt bn v

phng din c hc, v th hu ht cc my bin p hin nay u

dng kiu ghp ny.

Do dy qun thng qun thnh hnh trn, nn tit din

ngang ca tr thp thng lm thnh hnh bc thang gn trn

(hnh 2 8). Gng t v khng qun dy do , thun tin cho

Ghp ri li thp my bin p (hnh 2.6) Ghp xen k Li thp my bin p ba pha (hnh 2.7)



vic ch to, tit din ngang ca gng c th lm n gin: hnh

vung, hnh ch nht, hnh ch thp hoc hnh ch T (h nh2-9).

Tuy nhin, hin nay hu ht cc my bin p in lc, ngi ta

hay dng tit din gng hnh bc thang c s bc gn bng s bc

ca tit din tr.

Tit din tr thp (hnh2-8)

Tit din ca gng t (h nh2-9)

V l do an ton, ton b li thp c ni t vi v my v

v my phi c ni t.

- i vi tn silic cn ngui d hng, t thng lun i

theo chiu cn l chiu c t ln, l thp c ghp t cc l tn

c ct chp mt gc nht nh. Cch ghp li thp bng cc l tn

nh vy c s dng khi chiu dy l tn trong khong t 0,2

0,35mm. Khi chiu ny ca tn nh hn 0,2mm ngi ta dng

cng ngh mch t qun l tn v nh hnh dy 0,1. Vic qun

cc di tn c b rng khc nhau vi nhng dy ch ng vn

cho php thc hin mch t c tit din ngang c nhiu bc ni

tip trong vng trn. Khi cng sut nh v trung bnh s bc t 5

n 9, cn i vi nhng cng sut ln, s bc t 10 n 13.

+ Dy qun

Dy qun l b phn dn in ca my bin p lm, nhim

v thu nng lng vo v truyn nng lng ra. Kim loi lm dy

qun thng lm bng dy ng, cng c th lm bng nhm

nhng khng ph bin. Theo cch sp xp dy qun CA v HA,



ngi ta chia ra hai loi dy qun chnh: dy qun ng tm v

dy qun xen k.

- Dy qun ng tm : dy qun ng tm tit din ngang

l nhng vng trn ng tm. Dy qun HA thng qun pha

trong gn tr thp, cn dy qun CA qun pha ngoi bc ly dy

qun HA. Vi cch qun ny c th gim bt c iu kin cch.

in ca dy qun CA (kch thc dnh du cch in, v t

liu cch in dy qun CA) bi v gia dy qun CA v tr c

cch in bn chn ca dn qun.

Nhng kiu dy qun ng tm chnh bao gm:

- Dy qun h nh tr : nu tit din dy nh th dng dy

trn, qun thnh nhiu lp, nu tit din dy ln th dng dy bt

v thng qun thnh hai lp. Dy qun hnh tr dy trn thng

lm dy qun CA, in p ti 35KV. Dy qun hnh tr bt ch

yu lm dy qun HA vi in p di 6KV tr xung. Ni chung

dy cun hnh tr thng dng cho cc my bin p c dung lng

630KvA tr xung.

- Dy cun h nh son : gm nhiu dy bt chp li cun theo

ng xon c, gia cc vng dy c rnh h. Kiu ny thng



dng cho dy cun HA ca my bin p dung lng trung b nh v

ln.

- Dy qun xoy c lin tc: lm bng dy bt v khc vi

dy qun hnh xon ch dy qun ny c qun thnh nhng

bnh dy phng cch nhau bng nhng rnh h. Bng cch hon v

c bit trong khi qun, cc bnh dy c ni tip mt cch lin

tc. Dy qun ny ch yu lm bng cun CA, in p 35Kv tr

ln v dung lng ln.

- Dy cun xen k: cc bnh dy CA v HA ln lt xen k

nhau dc theo tr thp. Cn ch rng, thc hin d dng, cc

bnh dy st ngng thng thuc dy cun HA. Kiu dy cun ny

hay dng trong cc my bin p kiu bc. V ch to v cch in

kh khn, km vng trc v c hc nn my bin p kiu tr hu

nh khng dng kiu dy cun xen k.

2. My bin p khng ng b

a. S lc chung v my in khng ng b

My in khng ng b l loi my xoay chiu lm vic

theo nguyn l cm ng in t c tc quay ca roto khc vi

tc quay ca t trng 1. My in khng ng b c hai dy

qun, dy qun stato (s cp) ni vi li in tn s f1, dy qun

roto (th cp) c ni Tawts li v khp kn trn in tr. Dng

in trong dy qun roto ngha l ph thuc vo ti trn trc

my.

b. Phn loi v kt cu

1. Phn loi

My in khng ng b c nhiu loi c phn theo nhiu

cch khc nhau, theo kt cu ca v my, theo rt Theo v my,

my in khng ng b chia thnh: kiu h, kiu bo v, kiu

kn, kiu phng n. Theo kt cu ca roto: loi roto kiu dy qun



v loi roto kiu lng sc theo s pha trn dy qun c 3 loi: 1

pha 2 pha 3 pha.

3. Kt cu:

Ging nh my in quay khc my in khng ng b gm

c cc b phn chnh sau:

* Stato: l phn tnh gm hai b phn chnh l li thp v

dy qun ngoi ra cn c v my v np my. Li thp c p

trong v my lm nhim v dn t. Li thp stato hnh tr do cc

l thp k thut in c dp rnh bn trong ghp li vi nhau

to thnh cc rnh theo hng trc. V t trng i qua li thp l

t trng quay ln gim tn hao li thp c lm bng nhng

l thp k thut in dy 0,5mm p li. Mi l thp k thut u

ph sn cch in trn b mt gim tn hao do dng xoy gy

ln.

Dy qun stato c lm bng dy dn bc cch in (dy

in t) v c t trong. Cc thnh ca li thp kiu dy qun

hnh dng v cch b tr s c trnh by trong phn c s thi t

k dy qun sta to trong ng c khng ng b. V my lm bng

nhm hoc gang, dng c nh li thp v dy qun cng nh

c nh b my, khng dng lm mch dn t. i vi my c

cng sut ln (1000KV) thng dng thp tm hn li thnh v.

Tu theo cch lm ngui my m dng v cng khc nhau: kiu v

h, v bo v, v kn Hai u v c np my v trc. V my

v np my cn dng bo v my.

* Rto:

Rto l phn quay c li thp, dy qun v trc my

- Li thp

Ni chung li thp vn lm bng l thp k thut in nh

li thp ca stato. Li thp c p ln mt gc ca rto ca my

hoc p trc tip ln trc my.



- Dy qun roto

C hai loi dy chnh: rto lng sc v roto dy qun

Loi roto kiu dy qun: dy qun ging nh dy qun ca

sta to. Trong my in c trung b nh tr ln thng dng dy qun

ca stato. Trong my in c trung b nh tr ln thng dng dy

kiu sng 2 lp v bt c nhng u ni, kt cu dy qun cht

ch. Trong my in c nh thng dng dy qun ng tm mt

lp. Dy qun 3 pha ca roto thng u sao cn 3 u kia ni

vo 3 vnh trt thng lm bng ng c nh mt u trc v

thng qua chi than c th u vi mch in bn ngoi.

c im ca loi ng c in roto kiu dy qun l c th

thng qua chi than a in tr ph hay sut in ng vo mch

in roto ci thin h s cng sut m my. Khi my lm vic

bnh thng dy qun roto c ni ngn mch.

Loi roto kiu lng sc: kt cu ca loi dy qun ny rt

khc so vi dy qun stato. Trong mi rnh ca li thp roto t

vo thanh dn bng ng hay nhm di ra khi li thp v c

ni tt li hai u bng 2 vnh ngn mch bng ng hay nhm

lm thnh cc lng m ngi ta gi l lng sc.

my cng sut nh, lng sc c ch to bng cch c

nhm vo cc rnh li thp roto to thnh thanh nhm, hai u

c vng ngn mch v cch qut lm mt. dy qun roto lng sc

khng cn cch in vi li thp. ci thin tnh nng m my

trong my cng sut ln rnh roto c th lm thnh rnh su hoc

lm thnh 2 rnh (lng sc kp). Trong my in c nh rnh roto

thng lm cho o mt gc so vi tm trc.

ng c roto lng sc l loi rt ph bin do gi thnh r v

lm vic tin cy. ng c roto dy qun c u im v m my v

iu chnh tc ca ng c song gi thnh cao v vn hnh km

tin cy hn.



*. Khe h

V roto l mt khi trn nn khe h u, khe h trong my

in khng ng b rt nh (0,2 1mm) trong my in c nh v

va hn ch dng in t ho ly t li in v nh vy mi

c th nng cao h s cng sut m my.

4. Vai tr

My in khng ng b l loi my in xoay chiu ch

yu lm ng c in. Do kt cu n gin lm vic hiu qu cao,

gi thnh r nn ng c khng ng b l loi my c dng

rng ri nht trong nghnh kinh t quc dn vi cng t vi trc

n vo nghn KW. Trong cng nghip thng dng my in

khng ng b lm ngun ng lc cho cc my cn thp va v

nh, ng lc cho cc my cng nghip nh trong cc hm m

dng lm cc my ti hay qut gi. Trong i sng hng ngy my

ng c khng ng b cng chim v tr v cng quan trng: lm

qut gi, ng c trong t lnh c th ni vic sng ch ra n l

mt bc tin ca khoa hc k thut tuy nhin song song vi cc

u im trn th n cng tn ti hn ch nht nh: h s cng

sut m my thng khng cao, c tnh iu chnh tc khng

tt nn ng dng lm my pht in ca n b hn ch i nhiu.

My in khng ng b cn c th lm my pht in

nhng do nhng c tnh hn ch trn nn n khng c s dng

rng ri cho lm nhng trong mt s trng hp c bit vn cn

n d phng trong cc trng hp mt in.

5. Nguyn l lm vic:

To ra mt t trng quay vi tc n1 = 60f/p

Trong : f: l tn s dng in ca li a vo

p: l s i cc my.



Th t trng ny qut qua dy qun nhiu pha t ngn mch

trn li thp roto v cm ng trong dy qun sut in ng v

dng in. T thng s dng in ny s sinh ra hp vi t thng

ca stato to thnh thng tng khe h. Dng in trong dy qun

tc dng vi t thng khe h sinh ra omen tc dng do c tc dng

mt thit vi tc n ca roto. Trong nhng phm vi tc khc

nhau th ch lm vic ca my cng khc nhau.

Khi roto quay thun vi t trng quay nhng tc nh

hn tc ng b th dng in sinh ra trong dy qun roto cng

chiu vi sut in ng v tc dng t trng tng trong khe h

sinh ra lc F v momen M ko roto quay theo chiu t trng.

in nng a ti roto bin thnh c nng trn trc ngha l

my in lm vic trong ch ng c. nhng my ch lm vic

ch ny khi nn1). Khi chiu ca t trng quay qut qua dy dn

s c chiu ngc li sut in ng v dng in trong dy dn

roto cng i chiu nn chiu ca mmen cng ngc chiu quay

ca n1 ngha l ngc vi chiu ca roto nn l momen hm.

My in bin c nng tc dng ln trc ng c in do ng

c s cp kp thnh in nng cung cp cho li in ngha l

my in lm vic ch my pht in.

Khi roto quay ngc chiu vi chiu t trng quay th

chiu ca sut in ng, dng in v momen vn ging nh lc

ch ng c in. V momen sinh ra ngc chiu vi chiu

chy qua ca roto nn c tc dng hm ng li trong trng hp



ny my va ly in nng li vo, va ly c nng ng c

s cp ch lm vic ny gi l ch hm in.

III. C S THIT K B DY QUN MY BIP P V

NG C.

1. C s thit k ca b dy qun my bin p.

Cc thng s:

Q: Tit din li st.

S: Cng sut ca my bin p.

Wo: S vng cho mt Voll.

D: ng knh dy.

B: Tit din dy.

i: Mt dng in my bin p.

Cc bc tnh s liu dy qun my bin p mt pha.

Bc 1: Xc nh tit din Q ca li thp

Q = a b (cm x cm).

Q = S (i vi li ch O).

Q = 0,7S (i vi li ch E).

c p dng theo hnh v minh ho y l cu to ca cc

rnh khi ta qun dy vo bn trong cc rnh ny.

Bc 2: Tnh s vng dy ca cc cun dy.

2a a

b



Wo = (45 50)/ Q + (5 + 10)%) )ph thuc vo hm lng

silic cha trong thp).

S vng dy cun s cp W1 = Wo. U 1 (vng)

S vng dy cun th cp: khi t nh s vng dy cun th cp

phi d tr thm mt s vng dy b tr s sp p do tr

khng.

W2 = Wo (U2 + U2) vng.

d tr ca in p U2 c chn theo bng sau:

S (VA) 100 200 300 500 750 1000 1200 1500 >1500

4,5 4,5 3,9 3 2,5 2,5 2,5 2,5 2,0

Bc 3: Tit din dy, ng knh dy s cp v th cp khi

tnh t it din dy dn nn cn c vo iu kin lm vic ca my

bin p, cng sut M chn mt dng bin p cho ph hp

khi my bin p vn hnh nh mc dy dn khng pht nhit qu

80oC. Bng sau cho php mt dng in khi my bin p lm

vic lin tc 24/24.

S (VA) 050 50100 100200 200500 5001000

i 4 3,5 3 2,5 2

Nu my bin p lm vic ngn hn 3 5h thng gi tt ni

my bin p th c th chn i = 5 (A/mm*mm) tit kim

khi lng dy ng.

Thng thng ta chn i = 2,3 - 3(A/mm*mm)

Tit din dy s cp c chn theo cng thc:

Si = S CMTND /(U1 i) vi S1 = d1*d1/4

Suy ra c d1 = (4S2/1 i)



Vi l hiu sut my bin p (khong 0,85 0,90)

U1: l ngun in p ngun

Tit din dy th cp: S2 = I2/i v S2 = d2*d2/4

Suy ra ta c d2 = (4I2/i )

Bc 4: Kim tra li khong chng cha dy:

Trc ht xc nh cch b tr dy qun s cp v th cp.

Qun chng ln nhau hay qun 2 cun ri xa, t chn chiu di

L ca cun s cp, th cp qun dy trn khun cch in.

a. B dy cun s cp.

S vng dy s cp cho mt lp dy vi:

dlcd = d1 + ecd

W1 lp = L/d1cd 1 vi ecd = 0,03 0,08mm (emay)

ecd = 0,15 0,04 (bc ct tng)

S lp dy cun s cp: N = W1/W1 lp.

B dy ca cun s cp: 1 = (d2d N2lp) + ecd (N1lp 1)

+ B dy ca cun th cp: 2 = d2dN2lp + ecd (N2lp -

1).

+ B dy ton b ca c cun dy qun: tu theo s b tr

dy qun s cp v th cp m tnh b dy cun dy. Nu b dy

cun dy nh hn b rng ca s th c th tin hnh qun dy.

2. C s thit k b dy qun ng c khng ng b.

2.1. Cc khi nim v thng s c bn.

a. S cc P: c hnh thnh bi mt cun dy v c u dy

sao cho khi c dng in chy qua s to c cc cp cc N S

xen k k tip nhau trong mt pha. Khong cch t tm cc ny

n tm cc t k c gi l bc cc t T v bng 180 in.

Bc t T cn c hiu l khong cch nht nh hay gc

in gia pha A, pha B, pha C. Trong tnh ton T c tnh theo

n v v xc nh bng cng thc.



t = Z/ 2p trong Z l tng s rnh di mt cc.

b. Cun dy: c th l mt hoc nhiu vng khi cun dy c b

tr trn sta to th chia ra lm cc cnh dy v cc u dy (u ra ,

u vo.).

Bc dy qun l khong cch gia 2 cnh dy ca cun dy

ang c b tr trn stato v c tnh theo n v rnh k hiu

l y.

So snh bc cun dy vi bc cc t ta c:

- Bc y = t Z/2p

- Bc ngn yt

c. Cc thng s khc

M: S pha ca ng c.

a: S mch nhnh song song trong my.

Z: Tng s rnh dp trn my vi stato hoc roto.

Q: S rnh tc ng ln mt cc (tnh t cnh th nht n

cnh tc dng th 2 ca cng mt phn t)

Thng chn: q = Z/2mp = y/2p

d: Nhm cun dy.

Qun dy trong my in xoay chiu nh n chung c th thc

hin vi hai loi nhm dy: Nhm dy ng tm v nhm cun

dy ng khun.

+ Nhm cun dy ng tm: c hnh thnh bi nhiu cun

dy c bc cun dy khc nhau v c mc ni tip nhau theo

cng mt chiu qun. Cc cnh dy ca mi cun chim cc rnh

k cn nhau.



Dy qun ng khun Dy qun ng tm

to hnh nhm cun dy ng tm ngi ta qun lin tip

cc dy dn theo cng mt chiu qun ln trn mt b khun c

kch thc khc nhau v t ng tm trn cng mt trc qun.

u im: D lp t cun dy m stato.

Nhc im: Cc u cun dy chon ch nhiu hn i vi cc

cch qun khc.

2. Cch u dy gia cc nhm dy.

Mun dng s dy qun ng c 3 pha ta cn phi xc n

cc thng s sau ca stato.

Dng dy qun nh thit k

Tng s rnh Z ca phn stato.

S i cc 2P v cc u dy to cc tht hay gi.

Cc bc thc hin nh sau:

- Xc nh bc cc T = Z/2P.

- Tnh s cnh dy cho mi cc ca mi pha

i vi dy qun mt lp q = Z/(3.2P)(cnh dy)

i vi dy qun hai lp q = 2p = 2.Z/(3.2P)(cnh dy)

Tu theo cch phn b tri iu cc cnh dy t cc m

bc cun dy l bc hay .

- Tin hnh dng s theo cc bc.



+ K cc ng dy song song v nh s tng ng i vi

cc rnh ca stato.

+ Tri s cc dy 1 cc mi pha cho phn b u ti cc trc

cc t v xc nh chiu dng in theo chiu ca u dy.

Cn c vo cc dng qun nh dng v cc u cun dy ni

lin cc cnh dy gia cc nhm cun pha sao cho chiu dng

in ca cng mt bi trn cc cnh dy k tip khng b ngc

chiu nhau.

Da vo lch pha tnh, xc nh rnh khi u ca pha

B v tng t.

Cui cng v pha C tng t nh trn v cch pha B cng

bng lch pha trn

3. K thut qun dy.

y l mt phn quan trng i vi sinh vin ca bn em v

trong t thc tp cho bn em c tip xc vi cc loi my bin

p v ng c in. Ngi ta n i mt ngy ng hc mt

sng khn chnh v vy em hiu r v ng c in v my bin

p v chng em tn mt c tm hiu v chng.

4. K thut qun dy

y l mt phn quan trng trong t thc tp ny i vi

sinh vin.

n c chia thnh: - k thut qun dy my bin p

- k thut qun dy ng c

a. k thut qun dy my bin p

* Khun cch in

- Nhm mc ch cch in gia cun dy v mch t, ng

thi l sn cng nh h nh cun dy. Khun c lm bng

vt liu nh ct tng cng hoc giy cch in Press parn fibre

hoc bng cht do chu nhi t.

Khun khng vch chn c dng vi cc my bin p ln.



Khun c vch chn thng c dng vi cc my bin p

nh.

Kch thc ca khun c chn sao cho khng hp qu

hoc khng rng qu thun tin cho vic lp vo mc t khng b

cn d chm mt.

Sau khi ly khung cun dy thc hin khun lng cho kht

vi khun cch in.

b. K thut qun dy:

Trc khi qun dy phi v s b tr qun cc dy v tr

thc t sau khi ni mch khng b vng v d phn bit .

Khi qun dy, c nh u dy khi ng (h nh trn) trong

lc qun dy c gng qun dy cho thng v song song vi nhau.

C ht mi lp dy phi lt mt lp cch in i vi dy qu b

(d



dy li c hai u khun khi hon tt vic qun dy phi t ai

vi, giy cui cng lng dy v rt cht bng vi cho chc.

3. Cch rp mch t:

Tu theo dng l st ghp thnh mch t l dng EI hay l

cc thnh ch I ghp theo trt t cho trc.

*. Cch ghp mch t vi l st EI.

b. Cch ghp mch t t l thp ch I.

b. k thut qun dy stato ng c ba pha.



* Chun b khun.

Dng khun hnh qu chm.

5 . Cng ngh cun dy.

* Yu cu k thut.

Bi tp 1. Qun my in p gia dng c 4 u vo 80 - 110

160 220V v c cc nm iu chnh.

Bi tp 2. thc hin bi dy qun ng khun phn tn mt

lp vi cc thng s.

Z = 24, y = 5, q = 2, 2p = 4.

Bi tp 3. thc hin qun dy ng tm tp chung mt lp

vi cc thng s.

Z = 36, y = 9, q = 3, 2p = 4.

Cng ngh v s liu k thut

b. Qun my bin p gia dng c 4 u vo 80 110 160

220V c cc nm iu chnh in p 1 11.

S vng dy cc mc

220 160V l 60 x 1,2 = 72 vng.

160 110V l 50 x 1,2 = 60 vng.

110 80V l 30 x 1,2 = 36 vng.

h

L1

L2



Cc nm iu chnh, mi nm cch nhau 9 vng dy thc hin cch in ri qun dy trn khung g sau ng vo li thp. u ra mi nc t 10 15cm. c. Cng ngh qun dy: yu cu vut thng dy, ch xc, bong

cch in th phi tin hnh lt giy, yu cu dy qun phi cht,

cc vng dy xp st nhau v to thnh cc lp mc ch cho

hn ch tn hao kim loi ng v kch thc ca my bin p

thun li cho vic ng khung thp v sau. t lp giy cch in

0,3mm vo trong cng, sau ly mt u ra lm u 220V sau

qun 72 vng v a ra u 160V. Tip tc qun giy cch in v

2v v 4v 5v 6v 7v 8v 9v 10v 11v 12v 110v 150v 220v

9 vng/1 s

8 , 5 v ng

36 v n g

60 v n g 72 v n g

S qun dy trn thn mica ca my bin p



qun 60 vng ly u ra 110V. Tin hnh tng t ta s c u ra

80V sau khi qun 36 vng. Qun 8,5 vng sau thc hin

chuyn t thanh 80V sang thang 11V. Ri tin hnh qun ln lt

9 vng mt ly c cc u ra 10, 9 ,8 ,7 ,6, 5, 4, 3, 2, 1. Khi

qun cn ch cch in gia cc lp v cch in cc u ra

v lu v tr ph hp ca cc u dy ra khi lp vo b

chuyn mch cc u ra ny khng vt qua gng t.

Sau khi thc hin qun dy song, ta tho cun dy ra khi

khung g v t vo gng t. p cht gng v tr vng cch sit

cht cc ai c. Sau thc hin vic ni u ra vi cc cht trn

tip im. Cui cng mang ra kim tra.

Kt qu

- Chnh th

in p chun (V) 80 110 160 220

in p o c (V) 80 110 158 220

- Chnh tinh

Nm iu

chnh 1 2 3 4 5 6 7 8 9 10 11

in p (V) 110 112 117 122 128 130 138 142 148 155 165

Nhn xt:

u im: l hon thnh c sn phm cc u ra ng.

Nhc im: l hon thnh hi chm tnh thm m cha cao do

c s lm li trong qu trnh qun.

Kinh nghim: tuy sn phm u tay khng c nh mun

cho lm xong em cng thu c nhiu kinh nghim ring cho mnh



phn no hiu su hn v cu to ca my bin p cng nh cch

kim tra mt my bin p.

3.3. Qun dy ng khun tn 1 lp Z = 24, y = 5, q = 2, 2p = 4

- Qun dy: yu cu qun ring tng bi dy mt. Mi bi

qun 55 vng. Xc nh u ra u vo ng.

- Vo dy: trc tin vo dy ca 2 rnh ch l rnh 2,4. sau

thc hin vo bi th 1 rnh 1, rnh 6. Tip n l bi th 2

cc rnh 3, rnh 8. lm ln lt lin tip nh vy n khi ht s

bi dy, th ta h 2 cnh ch 21 v 23 xung.

Ch : vo y phi ch lt giy cch in 2 lp 0,1mm v

lp 0,3mm. giy cch in phi c gp trn v c bi no th

c gng kim tra thng mch cch in x l lun. v l bi tp

cho quen tay thc hin bi s 3 nn my khng cn chy th do

ta cng khng cn ai dy.

- u dy: ly u dy bt k lm pha A, ta t bi dy

l A1. Cch 2 bi lin tip s c u vo ca ln lt cc

qun A2, A3, A4. ta thc hin ni u ra A1 vi y ra A2, u

vo A2 ni vi u vo A3, u ra A3 ni u ra A4, cn li u

vo A4 chnh l u X. Tin hnh tng t ta c cch ni dy pha

B, C.

Nhn xt:

- u im: hon thnh c sn phm song cng khng t

c thm m mong mun bitc dng cch y dy v cch

xc nh cc u dy.

- Nhc im: l cha thnh tho trong cch vo dy do

cha quen, vic lm cc in cha t yu cu.

3.4. Qun dy ng tm tp chung 1 lp Z = 36, y = 9, q = 3, 2p

= 4

* Cng ngh



- Qun dy: yu cu mi bi dy 80 vng qun t cun nh

n cun ln, c dy tch ring tng bi.

- Vo dy: u tin ta phi xc nh chiu ca bi dy, u

ra u vo tng bi trnh b vo ngc u. Khi vo dy ta vo

cc rnh 1, 2, 3 v 10, 11, 12 ln cnh 4, 5, 6. Ri tip tc tin

hnh tng t n khi no ht cc bi dy th ta h 3 cnh cho vo

rnh 31, 32, 33. Lu rng khi vo dy, c bi no ta u phi

nn trn u dy, v p xung thun li cho vo bi dy tip

theo. Vo dy ln lt tng bi, t bi nh nht ri n bi ln

hn.

Khi vo dy xong phi ch gp lp cch in rnh li va

m bo thm m, va d dng cho chy roto sau ny

- u dy: tin hnh u dy nh s c. Cn ch co

lp emay cch in v t gel cch in vo cc u ni. Khi

u dy xong, ta phi nh du u vo v u ra A, B, C v X, y,

Z ca cc pha. Cui cng ta thc hin ai dy my cho gn gng,

cch 3 rnh ai 1 ln, chnh li cch in rnh, o li thng mch

v chun b lp rt v cho my cha th.



KT LUN

Qua thi gian thc tp ti Cng ty TNHH Hal Vit Nam. Em

thy y l 1 Cng ty sn xut in t dn dng rt pht tr in. Vi

cc thit b my mc tng i hin i, ph hp vi ngi s

dng. Ti y em tm hiu c v cc qu trnh lp t v

chc nng ca cc loi my mc. Vi s gip tn tnh ca cc

cn b k thut.

Nhng do iu kin thi gian v s hiu bit cn hn ch

nn em khng trnh khi nhng sai st. knh mong cc thy c

xem xt v gip em hon thnh tt bi bo co ny. em cng

xin gi li cm n n cc c ch trong Cng ty nhit tnh gip

em.

Qua y em cng c 1 s kin ngh nh sau:

- 1 s loi my mc cn lc hu cn thay 1 s loi my mc

khc hin i hn sn xut c hiu qu cao hn.

- Cng ty cn c 1 s chnh sch o to cng nhn k thut

c tay ngh cao, p dng nhng khoa hc k thut tin tin.



LI CM N Sau mt nm hc c s quan tm ca Nh trng, cng vi s ging dy nhit tnh ca cc thy c. chng em c th vn dng cc kin thc hc vo thc t cng nh hc hi thm kin thc t thc t. ban gim hiu v phng o to to nhng iu kin tt nht chng em c c st vi thc t v khng cn b ng sau khi ra trng v thc tp nhn thc l iu kin chng em c c st vi thc t. thc tp nhn thc t c kt qu tt Ban gim hiu c ra nhng gio vin c kinh nghim. Hng dn chng em nhng vn cn thit khi n c quan thc tp, cng chuyn thc tp. Chng em xin chn thnh cm n phng o to, Ban gim hiu Nh trng cng ton th cc thy c b mn tn tnh ging giy em. Nhng cng khng th khng nhc n Cng ty TNHH Hal Vit Nam to mi iu kin em c mt ni kin tp tt v hon thnh tt nhim v ca t thc tp ny. Em xin chn thnh gi li cm n ti Cng ty TNHH Hal Vit Nam v cc c ch trong Cng ty gip em trong sut qu trnh din tp ti c s. Em xin chn thnh cm n Ban gim hiu trng THBC Kinh t - K thut Bc Thng Long cng ton th cc thy c b mn to iu kin tt nht chng em c tm hiu v hc hi thm kinh nghim.

Vy mt ln na Em xin chn thnh cm n phng o to Nh trng, Cng ty TNHH Hal Vit Nam. c bit l nhng ngi trc tip hng dn, gip em trong sut qu tr nh thc tp nhn thc em c th vn dng nhng kin thc hc trong thc t v rt ra cho mnh nhng bi hc kinh nghim.

H Ni, ngy 29 thng 08 nm 2010

Sinh vin:

Lu Minh Thng

MC LC



Trang

LI NI U 1

NI DUNG BO CO 5

PHN I TM TT S QUA V NGNH IN 5

PHN II TM HIU CHUNG V CC B PHN MY IN

6

I KHI NIM V MY IN 6

1 S lc v my in 6

2 Vt liu ch to my in 7

II MY BIN P NG C 8

1 My bin p 8

2 My bin p khng ng b 16

III C S THIT K B DY QUN MY BIN

P V NG C 21

1 c s thit k b dy qun my bin p 21

2 c s thit k b dy qun ng c khng ng b 23

2.1 Cc khi nim v thng s c bn 23

2 Cch u dy gia cc nhm dy 25

3 K thut qun dy 26

1 Khun cch in 26

3 Cch lp rp mch t 28

5 Cng ngh qun dy 29

KT LUN 34

LI CM N 35

ng ta c thc hnh trn my theo mi ngnh hc ca

mnh. Nhng cn v thc t x hi th sao? Mt cu hi t ra cho



mi sinh vin m buc chng ta phi c cu tr li vi nhng vn

kin thc c bn v x hi m chng ta c hc.

V vy vic i thc tp l c hi p dng nhng k in thc

hc c Nh trng vo thc t x hi. Khng nhng th thc

tp cn gip cho chng ta hc tp v nng cao kin thc cho m nh.

ng thi cng gip chng ta hiu r thm v cng vic v thc

c tm qu trnh ca cng vic vi ngnh mnh ang theo hc,

vic i thc tp c tt hn v pht tr in hn na.

Bn cnh vic i thc tp cng rn luyn cho chng ta c

mt thc thc hin cc ni quy, quy nh ca Cng ty cng nh

cc c quan. ng thi buc chng ta phi chu trch nhim hon

ton vi nhng vic m nh v ang lm. gip em hon thnh

tt bi bo co thc tp nhn thc vi chuyn my bin p v

ng c.

H Ni, 29 thng 08 nm 2010

Hc Sinh:

Lu Minh Thng

i. tm hiu v c s thc tp

Cng ty TNHH Hal Vit Nam l Cng ty c thnh lp nm

2005. qua 5 nm thnh lp Cng ty ngy cng pht trin vi nhiu

mc tiu khc nhau. Nm KCn Bc Thng Long ng Anh -

HN vi mt v tr ht sc thun li cho vic giao lu v kinh

doanh vi cc Cng ty khc. l mt Cng ty chuyn lp t h

thng in, iu ho cho cc cng trnh v vy i hi nhng kh

nng lm vic rt tt. Khi c yu cu t khch hng lp tc cc



nhn vin k thut c ph bin nhim v v bt tay vo cng

vic ca m nh.

Ton b h thng iu hnh ca Cng ty c minh ho theo

s sau:

1. S B my t chc ca Cng ty TNHH Hal Vit Nam

2. Chc nng, nhim v cc b phn trong Cng ty TNHH Hal

Vit Nam

1. Gim c: l ngi lnh o v iu hnh v mi mt

hot ng ca Cng ty c th nh sau:

- K kt cc hp ng thi cng vi cc i tc.

- K kt cc giy t vn bn trong Cng ty.

- T chc v iu hnh cc cuc hp ca ban lnh o Cng

ty.

2. Ph Gim c: l ngi gip vic cho Gim c. Thay

mt Gim c iu hnh cc hot ng ca Cng ty khi Gim c

Gim c

Ph Gim c

Ph Gim c Trng phng k thut

Chuyn vin k thut

Nhn vin lp

t

Cng Nhn

SX

Th k

Ti v

K ton



i cng tc. Thc hin gii quyt cng vic khi c Gim c u

quyn.

Ch ng lp chng trnh cng tc, ch o cc cn b cng

nhn vin thuc phn ph trch lm vic theo ng quyn hn v

nhim v ca minh.

3. Trng phng k hoch: vch ra k hoch lm vic cho

cc phng ban trong Cng ty. Ch u trch nhim v cc hot ng

ca cc phng ban.

4. Trng phng k thut: chu trch nhim gim st v

thit k cc hng mc thi cng cc gi thu. Chu trch nhim

chnh v phn k thut thi cng, lp t.

5. K ton: l ngi chu trch nhim son tho cc giy t,

vn bn lin quan trong Cng ty. Trnh cc giy t cn k kt cho

Gim c. Xy dng k hoch thu chi hng thng.

6. Ti v: l ngi chu trch nhim qun l qu lng

trong Cng ty. K cc giy t thu chi ca Cng ty.

7. Nhn vin kho st thit k thi cng: chu trch nhim

kho st cng trnh cn thi cng lp t. V cc bn v thi cng

lp t.

8. Chuyn vin k thut: Chu trch nhim gim st cc

hot ng thi cng lp t ca cc nhn vin k thut.

9. Nhn vin lp t: l nhng cng nhn k thut tay ngh

cao trc tip vn chuyn v lp t thit b.

3. Ni quy ca Cng ty C phn Xy lp v ng dng Cng

ngh:

- Mi cn b cng nhn vin trong Cng ty phi chp hnh

ng theo quy nh m Cng ty ra.

- i lm ng gi.

+ Sng: t 7 gi n 11 gi.

+ Chiu: t 1 gi n 5 gi.



- Mi cn b cng nhn vin trong Cng ty phi nhit tnh

trong cng vic, lun phn u vi mc tiu uy tn v cht lng.

- Nhng phng ban, c nhn no c thnh tch tt s c

khen thng v tuyn dng.

- Mi c nhn u c ng bo him theo quy nh ca

php lut.

- Mi c nhn u c ngh l, ngh php hay ngh m theo

quy nh ca Nh nc.

- Cm mi c nhn lm vic ring, b vic t do trong gi

lm vic.

- Cm cc hnh vi sao chp, chm cp ti liu ca Cng ty.

Nu vi phm s b truy t trc php lut.

- Cm mi hnh vi chia b phi gy ri n i b trong Cng ty.

4. Nhng thun li, kh khn ca Cng ty TNHH Hal Vit

Nam trong qu trnh hnh thnh v pht trin

1. Thun li:

Cng ty TNHH Hal Vit Nam ra i trong thi k th trng

in t v cc thit b in t pht tr in mnh. Cng ty c

nhng iu kin v cng thun li gp phn vo s pht trin

ngy cng ln mnh ca Cng ty.

Cng ty ra i trong hon cnh t nc ta ang trong thi

k pht trin cng nghip ho in i ho nn c rt nhiu cc

nh my x nghip mc ln cc trung c c xy dng cng

nhiu, cc nh hng, khch sn to cho Cng ty c nhiu n

hng t Cng ty tch lu c nhiu kinh nghim thc t trong

lnh o v hot ng.



Bn cnh Cng ty cn c c mt thun li na l s

c gng, n lc ht sc m nh ca ton th cc cn b cng nhn

vin trong Cng ty gp phn xy dng Cng ty ngy cng vng

mnh, to c uy tn ln trn th trng.

2. Kh khn:

Trong nhng ngy u thnh lp i ng cn b, cng nhn

k thut tay ngh cao cn mng nn khng th trnh khi nhng

b ng ban u khi i vo hot ng.

Khi i vo hot ng Cng ty gp phi s cnh tranh khc

lit ca cc i th khc hn na cc trang thit b cn ngho

cng lm cho Cng ty c nhng hn ch nht nh.

Tuy nhin Cng ty tng bc khc phc c nhng hn

ch v i ng cn b k thut v trang thit b trong Cng ty.



Phn I. L thuyt v cc bi tp K thut in l mt ngnh rt quan trng trong cuc sng

hin nay. Ngi ta ng dng n trong mi lnh vc ca cuc sng

nh. Bin i nng lng o lng, iu khin v x l tn hiu

Trong c bit quan trng i vi cc ngnh thit b in n

gip sn xut ra cc thit b ng dng trong sinh hot ca con

ngi. Trong cuc sng hin nay my in c s dng ht sc

rng ri c bit i vi Vit Nam khi ang trong thi k in kh

ho v t ng ha th vai tr ca n ngy cng tr nn quan

trng. Cc pht minh lin tc c ra i nhiu cng ngh mi

c s dng phc v rt c lc cho con ngi.

i vi ngnh h thng in, chuyn ti nng lng in l

mt cng vic ht sc quan trng vi s tr gip ca cc my in

c bit l cc my bin p. Chng ta thu c nhiu hiu qu

v mt kinh t cng nh bo v mng li in.

Cn trong lnh vc sn xut vi s ra i ca cc ng c

in lm tng c nng sut lao ng.

Chnh v nhng l do nh vy nn trong chng trnh thc

tp ca khoa in trng THBC Kinh t - K thut Bc Thng

Long a vo nhng bi tp thc t. Nhm gip sinh vin nhn

thc c k thut cng nh cc nguyn l hot ng ca cc

thit b. Em xin chn thnh cm n cc thy, c trong ban ch

nhim khoa cng cc thy hng dn trong qu trnh thc tp.



Phn II. c s l thuyt v my in I. khi nim chung v my in

1. S lc v my in

My in l mt sn phm ca k thut in. N l mt h

thng in t gm c cc mch t v mch in c lin quan vi

nhau. Mch t gm cc b phn dn t v khe h khng kh, cc

mch in gm hai hoc nhiu dy qun c th chuyn ng tng

i vi nhau cng vi cc b phn mang chng.

N hot ng da trn nguyn l cm ng in t. Nguyn l

ny cng t c s cho s lm vic ca b bin i in nng, vi

nhng gi tr ca thng s ny (in p, dng) thnh in nng

vi cc gi tr thng s khc. My bin p l mt b bin i cm

ng n gin thuc loi ny, dng bin i dng in xoay

chiu t in p ny thnh in p khc, cc dy qun v mch t

ca n ng yn v qu trnh bin i t trng sinh ra sc

in ng cm ng trong cc dy qun c thc hin bng

phng php in.

My in dng lm my bin i nng lng l mt phn t

quan trng nht i vi bt c thit b in nng no. N c s

dng rng ri trong nng nghip, giao thng vn ti, cc h iu

khin v t ng iu chnh, khng ch.

My in c nhiu loi:

- My ng yn: My bin p.

- My in quay: Tu theo tng loi li in c th chia

lm hai loi my in xoay chiu v my in 1 chiu.

- My in xoay chiu c th phn chia thnh:

+ My in ng b.

+ My in khng ng b.

+ My in xoay chiu c vnh gt.



2. S lc v vt liu ch to my in:

Vt liu ch to my in c chia ra lm ba loi l: vt

liu tc dng vt liu kt cu v vt l iu cch in.

a. Vt liu tc dng : ch to my in gm vt liu dn

in v vt liu dn t. Cc vt liu ny c s dng to iu

kin cn thit sinh ra cc bin i in t.

* Vt liu dn t: ch to mch t ca my in. Ngi

ta dng cc loi thp t tnh khc nhau nhng ch yu l thp k

thut in, c hm lng silic khc nhau nhng khng qu 4,5%.

Hm lng c th hn ch tn hao do t tr v tng in tr ca

thp gim tn hao dng in xoy.

i vi my bin p ngi ta thng s dng ch yu l cc

l thp dy 0,35, 027mm, cn cc my in quay th ch yu l

thp c dy 0,5mm chng c ghp li gim tn hao dng

in xoy gy nn.

Ngy nay ngi ta sn xut v chia ra lm hai loi thp k

thut in.

+ Cn nng.

+ Cn ngui.

- Loi cn ngui c nhng c tnh t tt hn nh t thm

cao tn hao thp t hn loi cn nng. Thp cn ngui li c

chia lm 2 loi: d hng v ng hng

b. Vt liu dn in.

Vt liu thng dng l ng. ng dng lm dy dn khng

c c tp cht qu 0,1%. in tr xut ca ng 200 l P =

0,0172 .mm2/m. Nhm cng c dng rng ri lm vt liu dn

in. in tr sut ca nhm 200c l P = 0,0282 .mm2/m,

ngha l gn gp hai ln in tr sut ca



Cp cch Y A E B F H C

in

Nhit 90 105 120 130 155 180 >180

Cho php

c. Vt liu kt cu

Vt liu kt cu dng ch to cc b phn v chi tit

truyn ng hoc kt cu ca my theo cc dng cn tht, m bo

cho my in lm vic b nh thng. Ngi ta thng dng: ngang,

thp, cc kim loi mu, hp kim v cc vt liu bng cht do.

* Vt liu cch in:

vt liu cch in i hi c bn cao, dn nhit tt, chu

m, chu c ho cht v bn c cao.

i vi cc vt cch in th nhit nh hng rt nhiu

n tui th ca chng v th khi chng ta s dng cn ht sc ch

v nhit ni lm vic ca cc thit b.

Trn y l mt s cch nhn s loc nht v my in cng

nh cc nguyn l chung nht ca my in ng thi cng xt

qua v cc vt liu s dng trong k thut in. Sau y chng ta

tm hiu v b my bin p v cc my in xoay chiu.

II. My bin p v ng c

1. My bin p

a. S lc chung v my bin p

My bin p l thit b rt quan trng trong qu trnh truyn

ti in nng cng nh trong sn xut. N ra i t nhu cu kinh

t ca vic truyn ti lm sao cho t hiu qu kinh t nht.



S mng truyn ti in n gin (h nh 2.1)

My pht in ng dy ti

H tiu th

Nh chng ta bit, cng mt loi cng sut truyn ti trn

ng dy, nu bin p c tng cao th dng in chy trn

ng dy nh i, do trng lng v chi ph dy dn gim

xung. Ngy nay c rt nhiu cc loi my bin p, my bin p

s dng trong o lng (cc loi my bin p c cng sut nh) v

my bin p c cng sut ln s dng trong truyn ti (35kw, 110

kw, 220kw 500kw) Trong h thng in lc, mun truyn ti v

phn phi cng sut t cc nh my n cc h tiu dng mt cch

hp l, thng phi qua ba, bn ln tng v gim in p. Hin

nay cc bin p c s dng chuyn dng hn, chng c dng

trong cc ngnh chuyn mn, nba chuyn dng cho cc l luyn

kim, my bin p hn in my bin p cho cc thit b chnh

lu khuynh hng hin nay ca my bin p. nc ta hin nay

ngnh ch to my bin p ra i ngay t ngy ho bnh lp li.

n nay chng ta sn xut c mt khi lng kh ln my

bin p, vi nhiu chng loi khc nhau phc v cho nhiu ngnh

sn xut trong nc v xut khu. Hin nay sn xut c

nhng nba dung lng 63.000kVA vi in p 110KV.

ng dy dn

My bin p tng p My bin p gim p

u ra



b. Nguyn l lm vic ca my bin p

Ta xt s nguyn l ca mt my bin p nh hnh v.

y l my bin p mt pha dng hai dy qun. Dy qun

mt c W1 vng dy v dy qun hai c W2 vng dy c qun

trn li thp 3. Khi t mt in p xoay chiu U1 vo dy qun

1, trong s c dng in i1. Trong li thp s sinh ra t thng

mc vng c 2 cun dy 1 v 2, cm ng ra sut in ng e1

v e2. Dy qun 2 c s.. s sinh ra dng in i2 a ra ti vi

mt in p U2. nh vy.

Nng lng ca dng in xoay chiu c truyn t dy

qun 1 sang dy qun 2.

Gi s in p xoay chiu t vo l mt hm s Sin th cc

thng s m n sinh ra cng l mt hm s Sin = m. Sin t.

Do theo nh lut cm ng in t s.. trong cc cun

dy s l:

e1 = -W1.d /dt = -W1.dm.Sin t/dt = -W1mcos t

=

Tng t ta c:

Vi e1 = 4,44 f1m

UR

I2 I1

UV

)2/(12 tSine )2/(122 tSinee



E2 = 4,44 f2m

L cc gi tr hiu dng ca cc s.. dy qun 1 v 2

Cc biu thc trn cho thy l s.. cm ng trong dy qun

chm pha vi t thng sinh ra n mt gc /2

Da vo cc biu thc ca e1 v e2 ngi ta nh ngha t s

bin i ca my bin p nh sau: k = e1/e2 = W1/W2

Nu khng k in p ri trn cc dy qun th c th coi l

U1 e1 v U2 e2 v do k c xem nh l t s gia dy

qun 1 v 2.

c. Cc loi my bin p chnh

1. My bin p in lc dng truyn ti v phn phi

cng sut trong h thng in lc.

2. My bin p chuyn dng dng cho cc l luyn kim, cc

thit b chnh lu v my bin p dng hn in

3. My bin p t ngu bin i in p trong khong in

p khng ln, dng m my cho cc ng c in xoay chiu.

4. My bin p o lng dng gim in p khi c dng

in ln chy qua ng h o.

5. My bin p th nghim dng th nghim cc in p

cao

d. Cu to my bin p

My bin p c cc b phn chnh sauy: li thp, dy qun

v v my.

T thng

V 12

12



My bin p kiu li mt pha (h nh 2.3a)

Ba pha (hnh 2.3b)

+ Li thp: dng lm mch dn t, ng thi chng lm

khung qun dy qun theo h nh dng ca li thp ngi ta chia

ra:

- My bin p theo kiu li hnh tr (hnh 2 3): dy qun

bao quanh tr thp. Loi ny hin nay rt thng dng cho cc my

bin p mt pha v ba pha c dung lng nh v trung bnh.

- My bin p kiu bc: mch t c phn nhnh ra 2 bn

v bc ly mt phn dy qun. Loi ny thng ch dng trong

mt vi ngnh chuyn mn c bit nh: my bin p dng trong

l luyn kim hay my bin p dng trong thut v tuyn in,

truyn thanhvv.

cc My bin p hin i, dung lng ln v cc ln (80

100 MVA trn mt pha), in p tht cao (220 4000KV),

gim chiu cao ca tr thp, tin li cho vic vn chuyn trn

ng, mch t ca my bin p kiu tr c phn nhnh sang

hai bn nn my bin p mang hnh dng va kiu tr, va kiu

bc, gi l my bin p kiu tr bc ba pha (trng hp ny c

My bin p kiu tr bc

Tr bc m t pha Tr bc ba pha



dy qun ba pha, nhng c 5 tr thp nn cn gi l my bin p

ba pha nm tr).

Li thp my bin p gm 2 phn: phn tr k hiu bng

tr T v phn gong k hiu bng ch G (hnh 2 3). Tr l phn

li thp c qun dy qun: gng l phn li thp ni cc tr l i

vi nhau thnh mch t kn v khng c dy qun. i vi my

bin p kiu bc (hnh 2 4) v kiu tr bc (hnh 2 5), hai tr

thp pha ngoi cng u thuc v gng. gim tn hao do dng

in xoy gy nn, li thp c ghp t nhng l thp k thut

in dy 0,35mm c ph sn cch in trn b mt. Tr v gng

c th ghp vi nhau bng phng php ghp ni hoc ghp xen

k. ghp ni th tr v gng ghp ring, sau dng x p v bu

lng vt cht li (hnh 2-6). ghp xen k th ton b li thp phi

ghp ng thi v cc lp l thp c xp xen k vi nhau ln

lt theo trnh t a, b nh h nh 2-7. sau khi ghp, li thp cng

c vt cht bng x p v bulng. phng php sau tuy phc tp

song gim c tn hao do dng in gy nn v rt bn v

phng din c hc, v th hu ht cc my bin p hin nay u

dng kiu ghp ny.

Ghp ri li thp my bin p (hnh 2.6) Ghp xen k Li thp my bin p ba pha (hnh 2.7)



Do dy qun thng qun thnh hnh trn, nn tit din

ngang ca tr thp thng lm thnh hnh bc thang gn trn

(hnh 2 8). Gng t v khng qun dy do , thun tin cho

vic ch to, tit din ngang ca gng c th lm n gin: hnh

vung, hnh ch nht, hnh ch thp hoc hnh ch T (hnh2-9).

Tuy nhin, hin nay hu ht cc my bin p in lc, ngi ta

hay dng tit din gng hnh bc thang c s bc gn bng s bc

ca tit din tr.

Tit din tr thp (hnh2-8)

Tit din ca gng t (h nh2-9)

V l do an ton, ton b li thp c ni t vi v my v

v my phi c ni t.

- i vi tn silic cn ngui d hng, t thng lun i

theo chiu cn l chiu c t ln, l thp c ghp t cc l tn

c ct chp mt gc nht nh. Cch ghp li thp bng cc l tn

nh vy c s dng khi chiu dy l tn trong khong t 0,2

0,35mm. Khi chiu ny ca tn nh hn 0,2mm ngi ta dng

cng ngh mch t qun l tn v nh hnh dy 0,1. Vic qun

cc di tn c b rng khc nhau vi nhng dy ch ng vn

cho php thc hin mch t c tit din ngang c nhiu bc ni



tip trong vng trn. Khi cng sut nh v trung bnh s bc t 5

n 9, cn i vi nhng cng sut ln, s bc t 10 n 13.

+ Dy qun

Dy qun l b phn dn in ca my bin p lm, nhim

v thu nng lng vo v truyn nng lng ra. Kim loi lm dy

qun thng lm bng dy ng, cng c th lm bng nhm

nhng khng ph bin. Theo cch sp xp dy qun CA v HA,

ngi ta chia ra hai loi dy qun chnh: dy qun ng tm v

dy qun xen k.

- Dy qun ng tm : dy qun ng tm tit din ngang

l nhng vng trn ng tm. Dy qun HA thng qun pha

trong gn tr thp, cn dy qun CA qun pha ngoi bc ly dy

qun HA. Vi cch qun ny c th gim bt c iu kin cch.

in ca dy qun CA (kch thc dnh du cch in, v t

liu cch in dy qun CA) bi v gia dy qun CA v tr c

cch in bn chn ca dn qun.

Nhng kiu dy qun ng tm chnh bao gm:



- Dy qun hnh tr : nu tit din dy nh th dng dy

trn, qun thnh nhiu lp, nu tit din dy ln th dng dy bt

v thng qun thnh hai lp. Dy qun hnh tr dy trn thng

lm dy qun CA, in p ti 35KV. Dy qun hnh tr bt ch

yu lm dy qun HA vi in p di 6KV tr xung. Ni chung

dy cun hnh tr thng dng cho cc my bin p c dung lng

630KvA tr xung.

- Dy cun h nh son : gm nhiu dy bt chp li cun theo

ng xon c, gia cc vng dy c rnh h. Kiu ny thng

dng cho dy cun HA ca my bin p dung lng trung b nh v

ln.

- Dy qun xoy c lin tc: lm bng dy bt v khc vi

dy qun hnh xon ch dy qun ny c qun thnh nhng

bnh dy phng cch nhau bng nhng rnh h. Bng cch hon v

c bit trong khi qun, cc bnh dy c ni tip mt cch lin

tc. Dy qun ny ch yu lm bng cun CA, in p 35Kv tr

ln v dung lng ln.

- Dy cun xen k: cc bnh dy CA v HA ln lt xen k

nhau dc theo tr thp. Cn ch rng, thc hin d dng, cc

bnh dy st ngng thng thuc dy cun HA. Kiu dy cun ny

hay dng trong cc my bin p kiu bc. V ch to v cch in

kh khn, km vng trc v c hc nn my bin p kiu tr hu

nh khng dng kiu dy cun xen k.

2. My bin p khng ng b

a. S lc chung v my in khng ng b

My in khng ng b l loi my xoay chiu lm vic

theo nguyn l cm ng in t c tc quay ca roto khc vi

tc quay ca t trng 1. My in khng ng b c hai dy

qun, dy qun stato (s cp) ni vi li in tn s f1, dy qun



roto (th cp) c ni Tawts li v khp kn trn in tr. Dng

in trong dy qun roto ngha l ph thuc vo ti trn trc

my.

b. Phn loi v kt cu

1. Phn loi

My in khng ng b c nhiu loi c phn theo nhiu

cch khc nhau, theo kt cu ca v my, theo rt Theo v my,

my in khng ng b chia thnh: kiu h, kiu bo v, kiu

kn, kiu phng n. Theo kt cu ca roto: loi roto kiu dy qun

v loi roto kiu lng sc theo s pha trn dy qun c 3 loi: 1

pha 2 pha 3 pha.

3. Kt cu:

Ging nh my in quay khc my in khng ng b gm

c cc b phn chnh sau:

* Stato: l phn tnh gm hai b phn chnh l li thp v

dy qun ngoi ra cn c v my v np my. Li thp c p

trong v my lm nhim v dn t. Li thp stato hnh tr do cc

l thp k thut in c dp rnh bn trong ghp li vi nhau

to thnh cc rnh theo hng trc. V t trng i qua li thp l

t trng quay ln gim tn hao li thp c lm bng nhng

l thp k thut in dy 0,5mm p li. Mi l thp k thut u

ph sn cch in trn b mt gim tn hao do dng xoy gy

ln.

Dy qun stato c lm bng dy dn bc cch in (dy

in t) v c t trong. Cc thnh ca li thp kiu dy qun

hnh dng v cch b tr s c trnh by trong phn c s thi t

k dy qun sta to trong ng c khng ng b. V my lm bng

nhm hoc gang, dng c nh li thp v dy qun cng nh

c nh b my, khng dng lm mch dn t. i vi my c



cng sut ln (1000KV) thng dng thp tm hn li thnh v.

Tu theo cch lm ngui my m dng v cng khc nhau: kiu v

h, v bo v, v kn Hai u v c np my v trc. V my

v np my cn dng bo v my.

* Rto:

Rto l phn quay c li thp, dy qun v trc my

- Li thp

Ni chung li thp vn lm bng l thp k thut in nh

li thp ca stato. Li thp c p ln mt gc ca rto ca my

hoc p trc tip ln trc my.

- Dy qun roto

C hai loi dy chnh: rto lng sc v roto dy qun

Loi roto kiu dy qun: dy qun ging nh dy qun ca

sta to. Trong my in c trung b nh tr ln thng dng dy qun

ca stato. Trong my in c trung b nh tr ln thng dng dy

kiu sng 2 lp v bt c nhng u ni, kt cu dy qun cht

ch. Trong my in c nh thng dng dy qun ng tm mt

lp. Dy qun 3 pha ca roto thng u sao cn 3 u kia ni

vo 3 vnh trt thng lm bng ng c nh mt u trc v

thng qua chi than c th u vi mch in bn ngoi.

c im ca loi ng c in roto kiu dy qun l c th

thng qua chi than a in tr ph hay sut in ng vo mch

in roto ci thin h s cng sut m my. Khi my lm vic

bnh thng dy qun roto c ni ngn mch.

Loi roto kiu lng sc: k t cu ca loi dy qun ny rt

khc so vi dy qun stato. Trong mi rnh ca li thp roto t

vo thanh dn bng ng hay nhm di ra khi li thp v c

ni tt li hai u bng 2 vnh ngn mch bng ng hay nhm

lm thnh cc lng m ngi ta gi l lng sc.



my cng sut nh, lng sc c ch to bng cch c

nhm vo cc rnh li thp roto to thnh thanh nhm, hai u

c vng ngn mch v cch qut lm mt. dy qun roto lng sc

khng cn cch in vi li thp. ci thin tnh nng m my

trong my cng sut ln rnh roto c th lm thnh rnh su hoc

lm thnh 2 rnh (lng sc kp). Trong my in c nh rnh roto

thng lm cho o mt gc so vi tm trc.

ng c roto lng sc l loi rt ph bin do gi thnh r v

lm vic tin cy. ng c roto dy qun c u im v m my v

iu chnh tc ca ng c song gi thnh cao v vn hnh km

tin cy hn.

*. Khe h

V roto l mt khi trn nn khe h u, khe h trong my

in khng ng b rt nh (0,2 1mm) trong my in c nh v

va hn ch dng in t ho ly t li in v nh vy mi

c th nng cao h s cng sut m my.

4. Vai tr

My in khng ng b l loi my in xoay chiu ch

yu lm ng c in. Do kt cu n gin lm vic hiu qu cao,

gi thnh r nn ng c khng ng b l loi my c dng

rng ri nht trong nghnh kinh t quc dn vi cng t vi trc

n vo nghn KW. Trong cng nghip thng dng my in

khng ng b lm ngun ng lc cho cc my cn thp va v

nh, ng lc cho cc my cng nghip nh trong cc hm m

dng lm cc my ti hay qut gi. Trong i sng hng ngy my

ng c khng ng b cng chim v tr v cng quan trng: lm

qut gi, ng c trong t lnh c th ni vic sng ch ra n l

mt bc tin ca khoa hc k thut tuy nhin song song vi cc



u im trn th n cng tn ti hn ch nht nh: h s cng

sut m my thng khng cao, c tnh iu chnh tc khng

tt nn ng dng lm my pht in ca n b hn ch i nhiu.

My in khng ng b cn c th lm my pht in

nhng do nhng c tnh hn ch trn nn n khng c s dng

rng ri cho lm nhng trong mt s trng hp c bit vn cn

n d phng trong cc trng hp mt in.

5. Nguyn l lm vic:

To ra mt t trng quay vi tc n1 = 60f/p

Trong : f: l tn s dng in ca li a vo

p: l s i cc my.

Th t trng ny qut qua dy qun nhiu pha t ngn mch

trn li thp roto v cm ng trong dy qun sut in ng v

dng in. T thng s dng in ny s sinh ra hp vi t thng

ca stato to thnh thng tng khe h. Dng in trong dy qun

tc dng vi t thng khe h sinh ra omen tc dng do c tc dng

mt thit vi tc n ca roto. Trong nhng phm vi tc khc

nhau th ch lm vic ca my cng khc nhau.

Khi roto quay thun vi t trng quay nhng tc nh

hn tc ng b th dng in sinh ra trong dy qun roto cng

chiu vi sut in ng v tc dng t trng tng trong khe h

sinh ra lc F v momen M ko roto quay theo chiu t trng.

in nng a ti roto bin thnh c nng trn trc ngha l

my in lm vic trong ch ng c. nhng my ch lm vic

ch ny khi n



cp no quay roto ca my in khng ng b vt tc

ng b n>n1). Khi chiu ca t trng quay qut qua dy dn

s c chiu ngc li sut in ng v dng in trong dy dn

roto cng i chiu nn chiu ca mmen cng ngc chiu quay

ca n1 ngha l ngc vi chiu ca roto nn l momen hm.

My in bin c nng tc dng ln trc ng c in do ng

c s cp kp thnh in nng cung cp cho li in ngha l

my in lm vic ch my pht in.

Khi roto quay ngc chiu vi chiu t trng quay th

chiu ca sut in ng, dng in v momen vn ging nh lc

ch ng c in. V momen sinh ra ngc chiu vi chiu

chy qua ca roto nn c tc dng hm ng li trong trng hp

ny my va ly in nng li vo, va ly c nng ng c

s cp ch lm vic ny gi l ch hm in.

III. C s thit k b dy qun my bip p v ng c.

1. C s thit k ca b dy qun my bin p.

Cc thng s:

Q: Tit din li st.

S: Cng sut ca my bin p.

Wo: S vng cho mt Voll.

D: ng knh dy.

B: Tit din dy.

i: Mt dng in my bin p.

Cc bc tnh s liu dy qun my bin p mt pha.

Bc 1: Xc nh tit din Q ca li thp

Q = a b (cm x cm).

Q = S (i vi li ch O).

Q = 0,7S (i vi li ch E).



c p dng theo hnh v minh ho y l cu to ca cc

rnh khi ta qun dy vo bn trong cc rnh ny.

Bc 2: Tnh s vng dy ca cc cun dy.

Wo = (45 50)/ Q + (5 + 10)%) )ph thuc vo hm lng

silic cha trong thp).

S vng dy cun s cp W1 = Wo. U 1 (vng)

S vng dy cun th cp: khi t nh s vng dy cun th cp

phi d tr thm mt s vng dy b tr s sp p do tr

khng.

W2 = Wo (U2 + U2) vng.

d tr ca in p U2 c chn theo bng sau:

S (VA) 100 200 300 500 750 1000 1200 1500 >1500

4,5 4,5 3,9 3 2,5 2,5 2,5 2,5 2,0

Bc 3: Tit din dy, ng knh dy s cp v th cp khi

tnh t it din dy dn nn cn c vo iu kin lm vic ca my

bin p, cng sut M chn mt dng bin p cho ph hp

khi my bin p vn hnh nh mc dy dn khng pht nh it qu

2a a

b



80oC. Bng sau cho php mt dng in khi my bin p lm

vic lin tc 24/24.

S (VA) 050 50100 100200 200500 5001000

i 4 3,5 3 2,5 2

Nu my bin p lm vic ngn hn 3 5h thng gi tt ni

my bin p th c th chn i = 5 (A/mm*mm) tit kim

khi lng dy ng.

Thng thng ta chn i = 2,3 - 3(A/mm*mm)

Tit din dy s cp c chn theo cng thc:

Si = S CMTND /(U1 i) vi S1 = d1*d1/4

Suy ra c d1 = (4S2/1 i)

Vi l hiu sut my bin p (khong 0,85 0,90)

U1: l ngun in p ngun

Tit din dy th cp: S2 = I2/i v S2 = d2*d2/4

Suy ra ta c d2 = (4I2/i )

Bc 4: Kim tra li khong chng cha dy:

Trc ht xc nh cch b tr dy qun s cp v th cp.

Qun chng ln nhau hay qun 2 cun ri xa, t chn chiu di

L ca cun s cp, th cp qun dy trn khun cch in.

a. B dy cun s cp.

S vng dy s cp cho mt lp dy vi:

dlcd = d1 + ecd

W1 lp = L/d1cd 1 vi ecd = 0,03 0,08mm (emay)

ecd = 0,15 0,04 (bc ct tng)

S lp dy cun s cp: N = W1/W1 lp.

B dy ca cun s cp: 1 = (d2d N2lp) + ecd (N1lp 1)



+ B dy ca cun th cp: 2 = d2dN2lp + ecd (N2lp -

1).

+ B dy ton b ca c cun dy qun: tu theo s b tr

dy qun s cp v th cp m tnh b dy cun dy. Nu b dy

cun dy nh hn b rng ca s th c th tin hnh qun dy.

2. C s thit k b dy qun ng c khng ng b.

2.1. Cc khi nim v thng s c bn.

a. S cc P: c hnh thnh bi mt cun dy v c u dy

sao cho khi c dng in chy qua s to c cc cp cc N S

xen k k tip nhau trong mt pha. Khong cch t tm cc ny

n tm cc t k c gi l bc cc t T v bng 180 in.

Bc t T cn c hiu l khong cch nht nh hay gc

in gia pha A, pha B, pha C. Trong tnh ton T c tnh theo

n v v xc nh bng cng thc.

t = Z/ 2p trong Z l tng s rnh di mt cc.

b. Cun dy: c th l mt hoc nhiu vng khi cun dy c b

tr trn sta to th chia ra lm cc cnh dy v cc u dy (u ra ,

u vo.).

Bc dy qun l khong cch gia 2 cnh dy ca cun dy

ang c b tr trn stato v c tnh theo n v rnh k hiu

l y.

So snh bc cun dy vi bc cc t ta c:

- Bc y = t Z/2p

- Bc ngn yt

c. Cc thng s khc

M: S pha ca ng c.

a: S mch nhnh song song trong my.

Z: Tng s rnh dp trn my vi stato hoc roto.



Q: S rnh tc ng ln mt cc (tnh t cnh th nht n

cnh tc dng th 2 ca cng mt phn t)

Thng chn: q = Z/2mp = y/2p

d: Nhm cun dy.

Qun dy trong my in xoay chiu nh n chung c th thc

hin vi hai loi nhm dy: Nhm dy ng tm v nhm cun

dy ng khun.

+ Nhm cun dy ng tm: c hnh thnh bi nhiu cun

dy c bc cun dy khc nhau v c mc ni tip nhau theo

cng mt chiu qun. Cc cnh dy ca mi cun chim cc rnh

k cn nhau.



Dy qun ng khun Dy qun ng tm

to hnh nhm cun dy ng tm ngi ta qun lin tip

cc dy dn theo cng mt chiu qun ln trn mt b khun c

kch thc khc nhau v t ng tm trn cng mt trc qun.

u im: D lp t cun dy m stato.

Nhc im: Cc u cun dy chon ch nhiu hn i vi cc

cch qun khc.

2. Cch u dy gia cc nhm dy.

Mun dng s dy qun ng c 3 pha ta cn phi xc n

cc thng s sau ca stato.

Dng dy qun nh thit k

Tng s rnh Z ca phn stato.

S i cc 2P v cc u dy to cc tht hay gi.

Cc bc thc hin nh sau:

- Xc nh bc cc T = Z/2P.

- Tnh s cnh dy cho mi cc ca mi pha

i vi dy qun mt lp q = Z/(3.2P)(cnh dy)

i vi dy qun hai lp q = 2p = 2.Z/(3.2P)(cnh dy)

Tu theo cch phn b tri iu cc cnh dy t cc m

bc cun dy l bc hay .



- Tin hnh dng s theo cc bc.

+ K cc ng dy song song v nh s tng ng i vi

cc rnh ca stato.

+ Tri s cc dy 1 cc mi pha cho phn b u ti cc trc

cc t v xc nh chiu dng in theo chiu ca u dy.

Cn c vo cc dng qun nh dng v cc u cun dy ni

lin cc cnh dy gia cc nhm cun pha sao cho chiu dng

in ca cng mt bi trn cc cnh dy k tip khng b ngc

chiu nhau.

Da vo lch pha tnh, xc nh rnh khi u ca pha

B v tng t.

Cui cng v pha C tng t nh trn v cch pha B cng

bng lch pha trn

3. K thut qun dy.

y l mt phn quan trng i vi sinh vin ca bn em v

trong t thc tp cho bn em c tip xc vi cc loi my bin

p v ng c in. Ngi ta n i mt ngy ng hc mt

sng khn chnh v vy em hiu r v ng c in v my bin

p v chng em tn mt c tm hiu v chng.

4. K thut qun dy

y l mt phn quan trng trong t thc tp ny i vi

sinh vin.

n c chia thnh: - k thut qun dy my bin p

- k thut qun dy ng c

a. k thut qun dy my bin p

* Khun cch in

- Nhm mc ch cch in gia cun dy v mch t, ng

thi l sn cng nh h nh cun dy. Khun c lm bng



vt liu nh ct tng cng hoc giy cch in Press parn fib re

hoc bng cht do chu nhi t.

Khun khng vch chn c dng vi cc my bin p ln.

Khun c vch chn thng c dng vi cc my bin p

nh.

Kch thc ca khun c chn sao cho khng hp qu

hoc khng rng qu thun tin cho vic lp vo mc t khng b

cn d chm mt.

Sau khi ly khung cun dy thc hin khun lng cho kht

vi khun cch in.

b. K thut qun dy:

Trc khi qun dy phi v s b tr qun cc dy v tr

thc t sau khi ni mch khng b vng v d phn bit.

Khi qun dy, c nh u dy khi ng (h nh trn) trong

lc qun dy c gng qun dy cho thng v song song vi nhau.

C ht mi lp dy phi lt mt lp cch in i vi dy qu b

(d



in, vic ni dy gia chng cng phi a mi ni ra ngoi

cun dy,

i vi khun khng c vch chn dy, gi cc lp dy

khng b chy ra ngoi khun phi dng bng vi hoc giy chc

dy li c hai u khun khi hon tt vic qun dy phi t ai

vi, giy cui cng lng dy v rt cht bng vi cho chc.

3. Cch rp mch t:

Tu theo dng l st ghp thnh mch t l dng EI hay l

cc thnh ch I ghp theo trt t cho trc.

*. Cch ghp mch t vi l st EI.

b. Cch ghp mch t t l thp ch I.



b. k thut qun dy stato ng c ba pha.

* Chun b khun.

Dng khun hnh qu chm.

5 . Cng ngh cun dy.

* Yu cu k thut.

Bi tp 1. Qun my in p gia dng c 4 u vo 80 - 110

160 220V v c cc nm iu chnh.

Bi tp 2. thc hin bi dy qun ng khun phn tn mt

lp vi cc thng s.

Z = 24, y = 5, q = 2, 2p = 4.

Bi tp 3. thc hin qun dy ng tm tp chung mt lp

vi cc thng s.

Z = 36, y = 9, q = 3, 2p = 4.

Cng ngh v s liu k thut

h

L1

L2



b. Qun my bin p gia dng c 4 u vo 80 110 160

220V c cc nm iu chnh in p 1 11.

S vng dy cc mc

220 160V l 60 x 1,2 = 72 vng.

160 110V l 50 x 1,2 = 60 vng.

110 80V l 30 x 1,2 = 36 vng.

Cc nm iu chnh, m i nm cch nhau 9 vng dy thc hin cch in ri qun dy trn khung g sau ng vo li thp. u ra mi nc t 10 15cm.

2v v 4v 5v 6v 7v 8v 9v 10v 11v 12v 110v 150v 220v

9 vng/1 s

8 , 5 v ng

36 v n g

60 v n g 72 v n g

S qun dy trn thn mica ca my bin p



c. Cng ngh qun dy: yu cu vut thng dy, ch xc, bong

cch in th phi tin hnh lt giy, yu cu dy qun phi cht,

cc vng dy xp st nhau v to thnh cc lp mc ch cho

hn ch tn hao kim loi ng v kch thc ca my bin p

thun li cho vic ng khung thp v sau. t lp giy cch in

0,3mm vo trong cng, sau ly mt u ra lm u 220V sau

qun 72 vng v a ra u 160V. Tip tc qun giy cch in v

qun 60 vng ly u ra 110V. Tin hnh tng t ta s c u ra

80V sau khi qun 36 vng. Qun 8,5 vng sau thc hin

chuyn t thanh 80V sang thang 11V . Ri tin hnh qun ln lt

9 vng mt ly c cc u ra 10, 9 ,8 ,7 ,6, 5, 4, 3, 2, 1. Khi

qun cn ch cc

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