Báo cáo thực tập xưởng điện

8/2/2019 Bo co thc tp xng in

1/20

Bo co thc tp xng in HBKHN

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Mc lc..1

LI MU ....2

PHN I. L THUYT MY IN.....3I. TNG QUAN VMY IN.....31. Khi nim chung....32. Phn loi . . 33. Cu to chung. . 44. Nguyn l lm vic c bn. . 45. Cc thng schnh .....56. Vt liu ch to ..57. Pht nng v lm mt dy qun. .6

II. MY BIN P. .6

1. Khi nim chung. .62. Cu to . 73. Nguyn l lm vic. .8

III. MY IN KHNG NG B ...91. Khi nim chung. 92. Cu to 103. Nguyn l lm vic 11

PHN II. THC HNH QUN DY STATO NG C KHNG NG B12I. DY QUN STATO NG C KHNG NG B..12

1. Mt si lng c trng .122. Mt s cng thc tnh ton . 123. Phn loi. . 124. Yu cu ..135. Qun dy stato ng c khng ng b . 13

II. THC HIN QUN DY NG C KHNG NG B.. 141. Bi tp 1 : qun dy ng khun phn tn 1 lp. 142. Bi tp 2 : qun dy ng tm tp trung 1 lp...17

KT LUN ......20


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LI MU

Vi mi sinh vin ngoi vic tip thu kin thc l thuyt trn ging ng th vic tip xc thct l yu cu khng th thiu i vi sinh vin. Do thc tp l mt trong nhng yu cu tt yuca sinh vin bt ctrng i hc no trn cnc. L thuyt trn sch vphi i km vi thctin th sinh vin mi thc s c th hiu r l thuyt hc ng thi trang bc phn no kinthc thc tgip sinh vin sau khi tt nghip ra trng c th nm bt v ho nhp tt vicng vic thc tin v khng bm h v cng vic trong tng lai.

Trng i hc Bch Khoa H Ni l mt trng k thut, thc hin phng chm hc i ivi hnh hng nm u t chc cho sinh vin giai on o to chuyn ngnh c i thc tp.Mc d kinh ph v c svt cht cn hn hp, song nh trng, khoa in ni chung v b mnThit bin-in tni ring ht sc to iu kin cho chng em c thi gian thc tp ti xng

in lm quen vi cc thit b my mc dng c, thc hnh v kim tra li kin thc.

Thi gian ch c 3 tun, tuy khng thc s nhiu nhng thc squ gi i vi chng em, gipchng em c ci nhn trc quan hn, cng c cc kin thc hc.

Em xin chn thnh cm n khoa v bmn to iu kin cho chng em c thc hnh tixng, c bit l cc thy c tn tnh hng dn, gip chng em hon thnh tt t thc tpva qua.

Sau y em xin trnh by cc ni dung thu hoch c qua t thc tp ti xng in :

- Phn 1 : L thuyt : l thuyt vmy in.- Phn 2 : Thc hnh : thc hnh qun dy ng c khng ng b3 pha ng khun phn tn 1 lpv ng tm tp trung 1 lp.


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PHN I. L THUYT MY IN.

I. TNG QUAN VMY IN.1. Khi nim chung.

Trong qu tnh khai thc s dng cc ti nguyn thin nhin phc v cho nn kinh t quc dn,khng thkhng ni n s bin i nng lng t dng ny sang dng khc.

Cc thit bin t thc hin s bin i c nng thnh in nng hoc tin nng thnh cnng da trn nguyn l cm ng in tc gi l my in.

My in dng lm my bin i nng lng l phn t quan trng nht ca bt c thit binnng no. N c s dng rng ri trong cng nghip, nng nghip, giao thng vn ti, cc hiukhin v tng iu chnh khng ch

2. Phn loi.My in c nhiu loi v c nhiu cch phn bit chng nh:- Phn loi theo cng sut.- Phn loi theo cu to.- Phn loi theo chc nng.- Phn loi theo dng in (mt chiu v xoay chiu).

- Phn loi theo nguyn l lm vic.S tm tt phn loi my in :

Nhng y ta phn loi theo nguyn l bin i nng lng nh sau :- My in tnh.(H1)My in tnh lm vic da trn hin tng cm ng in t, do s bin i t thng gia cc

cun dy khng c chuyn ng tng i vi nhau.


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My in tnh thng gp l my bin p. My in tnh dng bin i thng s ca dngin, nh my bin p bin i hai thng s ca dng in l gi tr p v gi tr dng.

- My in quay.(H2)Nguyn l lm vic cng da vo hin tng cm ng in t, lc in t, do ttrng v dng

in ca cc cun dy c chuyn ng tng i vi nhau gy ra.Loi my ny thng dng bin i cc dng nng lng. Cc my in bin i c nng

thnh in nng c gi l cc my pht in v cc my in dng bin i ngc li c gil ng c in. Cc my in u c tnh thun nghch, ngha l u c th bin i nng lngtheo hai chiu. Nu a c nng vo phn quay th my in s lm vic ch my pht, nua in nng vo th phn quay ca my ssinh ra cng c hc.

3. Cu to chung.My in gm c mch t (khp kn bi li thp) v mch in (cc cun dy) lin quan cht

ch ti nhau, dng bin i qua li gia cc dng nng lng nh in nng thnh cc dng nnglng khc (ng c in) hay ngc li t cc dng nng lng khc thnh in nng (my phtin) hoc dng bin i cc thng sin nng nh bin i in p dng in,tn s,spha

Li thp ca my in l mch tkhp kn dn t thng, cn cc mch in gm hai haynhiu dy qun c th chuyn ng tng i vi nhau cng cc b phn g lp.

4. Nguyn l lm vic c bn.My in lm vic da trn nguyn l cm ng in t. N tun ththeo 2 nh lut l: nh

lut cm ng in t(nh lut Faraday) v nh lut v lc in t(nh lut Laplace).4.1. nh lut cm ng in t. Pht biu: S bin thin tng t thng mc vng trong mch in s to ra mt sc in ng tl vi o hm ca tng t thng bin thin .

Biu thc:d

edt

Trong : e : sut in ng cm ng: tng t thng mc vng trong mch in

Dng khc: . .e B l v Trong : e : sc in ng cm ng

B : t cm

l : chiu di thanh dn trong ttrngv : tc chuyn ng ca thanh dn theo hng vung gc vi t cm

4.2. nh lut v lc t. Pht biu: Lc in t tc dng ln thanh dn mang dng in t trong ttrng c ln tl thun vi chiu di ca thanh dn, cng dng in chy qua thanh dn v cng ttrngni cha thanh dn. Biu thc: . . .sin f B l i Trong : f : lc in t tc dng ln thanh dn

B : cng ttrng


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l : chiu di thanh dni : cng dng in trong thanh dn

: gc gia vc t t cm vi dng in i chy trong thanh dn

5. Cc thng s chnh.Mi mt my in c mt b cc thng snh mc m bo khi vn hnh my c tht

c hiu sut cao nht, n nh v an ton nht ng thi m bo bn, tui th my. Qua ccthng s ca my in ta cng c th chn c loi my in ph hp vi yu cu s dng

Cc thng sni chung thng dng l: in p nh mc, dng in nh mc, dung lng vcng sut nh mc, tc nh mc

6. Vt liu ch to.6.1. Vt liu tc dng.

Vt liu tc dng gm vt liu dn t v vt liu dn in. Cc vt liu ny s lm nhim vthc hin cc chuyn i in ttrong my in. Vt liu dn t:

Dng ch to mch tcho my in. Ngi ta thng dng cc loi thp c tnh cht t khcnhau cho cc loi my in khc nhau. Loi thp thng dng l thp l k thut in, c hm lngSilic khc nhau nhng khng vt qu 4.5%. Hm lng Silic ny dng hn ch tn hao do t trv tng in trca thp gim tn hao do dng in xoy. Thng thng cc loi thp k thutin c b dy 0.35 hay 0.27 mm dng cho my bin p v 0.5mm dng cho my in quay. Cc lthp ny sc ghp li vi nhau gim tn hao do dng in Fuco gy nn. Theo cch ch tongi ta phn thp k thut in ra lm hai loi: cn nng v cn ngui. Thp cn ngui c c tnht tt hn thp cn nng. l t thm cao hn, tn hao thp t hn. Thp cn ngu i chia lm hailoi: dhng v ng hng. Loi dhng th tnh nng ttnh theo hng dc theo hng cn thtt hn hn do n thng c dng trong my bin p. Cn loi thp ng hng th c c tnht theo mi hng l nh nhau nn thng c dng trong my in quay. Vt liu dn in:

Thng dng l ng. ng dng lm dy qun phi t tiu chun tp cht khng qu 0.1%.Ngoi ra trong mt strng hp ngi ta cn dng nhm lm vt liu dn in.

6.2. Vt liu kt cu.L loi vt liu dng ch to ra cc b phn chi tit truyn ng hoc kt cu cho my in

theo cc dng cn thit, m bo cho my chy bnh thng. Ngi ta thng dng cc vt liu nhgang, thp, kim loi mu, hp kim hoc cc vt liu bng cht do.6.3. Vt liu cch in.

Dng ch to cc b phn ngn cch gia cc b phn mang in vi b phn khng mangin cng nh gia cc b phn mang in vi nhau (cc pha). Nhng vt liu ny c vai tr rtquan trng trong my in v n m bo s an ton trong sut qu trnh hot ng ca my. Do n cn m bo nhng yu cu nh bn nhit cao, dn nhit tt, chu m, chu c ha chtv c bn c nht nh.

V cc vt liu cch in c bn khc nhau nn ngi ta chia n ra thnh 7 loi theo cp nhit lm vic ca chng :

Cp cch in Y A E B F H CNhit lm vic 90 105 120 130 155 180 >180

Khi my lm vic, do cc tc ng khc ca iu kin lm vic m bn ca vt liu cch ins b gim. Theo thc nghim nu nhit lm vic cho php tng qu t 8-10C th tui th vt liucch in s gim i mt na. Do khi lm vic cn trnh my in qu ti lm tng nhit trong thi gian di.


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7. Pht nng v lm mt dy qun.Trong my in xy ra qu trnh bin i hoc truyn ti nng lng v c s tn hao nng lng

p . Trong my pht in tn hao ch yu l trong li thp( do hin tng t tr v dng xoy),trong in trdy qun my in v do ma st cc trc, lc cn ca qut lm mt my pht in... tn hao ny lm nng my v nh hng n cht lng ca vt liu cch in.

lm mt my in, nhit lng sinh ra phi c tn ra mi trng xung quanh bng cch tngdin tch tip xc ca my in vi khng kh lm mt, tng tc i lu ca khng kh xungquanh hoc ca mi trng lm mt. Thng vmy in, c ch to c cnh ti nhit v i vimy in c cng sut ln thng c h thng qut gi hoc bm nc lm mt.

Kch thc ca my, phng php lm mt phi c tnh ton v la chn, cho tng nhitca vt liu cch in my khng vt qu tng nhit cho php, m bo cho vt liu cch inlm vic lu di khong 20 nm.

Khi my in lm vic chnh mc, tng nhit ca cc phn tkhng vt qu tngnhit ca cc phn t cho php. Khi my qu ti, tng nhit svt qu nhit cho php, v thkhng cho php qu ti lu di.

II. MY BIN P.

1. Khi nim chung. bin i in p ca dng in xoay chiu tin p cao xung in p thp hoc ngc li

ta s dng my bin p. Ngy nay do vic s dng in nng pht trin rng ri nn c nhng limy bin p khc nhau: 1 pha, 3 pha, 2 day qun, 3 dy qun nhng chng u da trn mtnguyn l - nguyn l cm ng in t.1.1. nh ngha.

My bin p l mt thit bin t loi tnh, lm vic theo nguyn l cm ng in t, bin imt h thng dng in xoay chiu in p ny thnh mt h thngdng in xoay chiu in pkhc vi tn skhng thay i.

Do my bin p ch lm nhim v truyn ti hoc phn phi nng lng ch khng bin inng lng.

u vo ca my bin p ni vi ngun in c gi l s cp, u ra ni vi ti gi l thcp. Cc i lng thng ss cp trong k hiu ghi ch s 1: svng dy s cp N1, in p s cpU1, dng in s cp I1, cng sut s cp P1 Tng t bn th cp c ch s 2: N2, U2, I2, P21.2. Cng dng.

My bin p c vai tr quan trng trong h thng in. N l 1 khu quan trng dng truynti v phn phi in nng. Cc nh my in cng sut ln thng xa cc trung tm tiu thinv th cn phi xy dng cc ng dy truyn ti in.

in p my pht thng l 6.3, 10.5, 15.75, 38.5 kV. nng cao khnng truyn ti v gimtn hao cng sut trn ng dy phi gim dng in chy trn ng dy bng cch nng cao inp. V vy u ng dy cn t my bin p tng p. Mt khc in p ca ti thng khong 127ti 500V, ng c cng sut ln thng 3 ti 6 kV, v vy cui ng dy cn t my bin p gim

p.

Ngoi ra, my bin p cn c dng trong cc l nung, hn in, o lng hoc lm ngunin cho cc thit bin, in t cn nhiu cp in p khc nhau


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1.3. Phn loi. Theo s pha: my bin p mt pha v my bin p ba pha. Theo cng dng:

- My bin p in lc: lm nhim v truyn ti v phn phi in nng.- My bin p chuyn dng: dng cho cc mc ch c thnh luyn kim, hn- My bin p t ngu: dng bin i in p trong phm vi khng ln.- My bin p o lng: gim in p, gim dng in khi a vo cc ng ho.- My bin p th nghim: dng th nghim cc in p cao.

1.4. Mt si lng nh mc.- Dung lng hay cng sut nh mc Sm: cng sut ton phn( biu kin) a ra th cp.- in p v dng in dy s cp nh mc U1m, I1m.- in p v dng in dy th cp nh mc U2m, I2m.- Tn snh mc fm.

2. Cu to.My bin p c cu to t ba b phn chnh: li thp, dy qun v v my. Ty vo tng

nhim vkhc nhau m chng c cu to t nhng loi vt liu khc nhau.2.1. Li thp.

Li thp c dng lm mch dn t, ng thi lm khung qun dy qun. Theo hnh dngli thp, ngi ta chia ra my bin p kiu li v my bin p kiu bc.

Li thp my bin p c lm t tn silic cn ngui dhng, tthng lun i theo chiucn l chiu c t dn ln, l thp c ghp tcc l tn c ct cho mt gc nht nh. Cchghp ny dng trong cc mch tc dy tm tn trong khong t 0.20-0.35 mm. Khi b dy tmtn nhhn 0.20 mm ngi ta dng cng ngh mch t qun l tn v dnh hnh dy 0.10 mm.

Li thp ca my bin p bao gm 2 phn.- Phn tr: l phn qun dy.- Phn gng: Kt ni cc phn tr li v to thnh mch t kn.Trv gng c p cht vi nhau bng c vt.Do dy qun thng qun thnh hnh trn, nn tit din ngang ca trthp thng lm thnh

hnh bc thanh gn trn. Gng v khng qun dy, do thun tin cho vic ch to, tit dinngang ca gng c thlm n gin: hnh vung, hnh ch thp v hnh T. V l do an ton, ton bli thp c ni t vi v my v v my phi c ni t.

Ty theo hnh dng, ngi ta chia ra:- My bin p kiu li( hay kiu tr): 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: Loi ny mch tc phn nhnh ra 2 bn v bc ly mt phn dy

qun. Loi ny chc dng cho mt vi ngnh c chuyn mn c bit nh my bin p dngtrong l in luyn kim

- cc my bin p hin i, dung lng ln v cc ln(80-100MVA trn 1 pha), in p thtcao (220400 kV), gim chiu cao ca tr thp, tin li cho vic vn chuyn trn ng, mch

t ca my bin p kiu tr 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.2.2. Dy qun.

Cng dng: l b phn dn in ca my bin p, lm nhim vthu nng lng vo v truynnng lng ra. Kim loi dng lm dy qun thng bng ng. Theo cch qun dy s cp v thcp ta c th chia thnh hai loi. Dy qun ng tm v dy qun xem k. Dy qun ng tm.


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L dy qun m tit din ngang l nhng vng trn ng tm. Dy qun hp thng qun pha trong cn dy qun cao p qun bn ngoi tn dng qun h p lm lp phn cch giacun cao p v tr. Nhng kiu dy qun ng tm chnh l:

- Dy qun hnh tr: Nu tit din dy nh th dng dy trn, qun nhiu lp. Nu t it din dyln th dng dy bt v qun thnh hai lp. Dy qun hnh trdy trn thng dng lm dy quncao p, in p ti 35 kV, dy qun hnh tr bt dng ch yu lm dy qun h p vi in p t 6kVtrxung. Ni chung dy qn hnh trthng dng cho cc my bin p c dung lng 630kVA trxung.

- Dy qun hnh xon: Gm nhiu dy bt chp li qun theo ng xon c, gia cc vng dyc rnh h. Hnh kiu ny thng dng cho cc my bin p c dung lng trung bnh v ln.

- Dy qun xoy xon c lin tc : lm bng dy bt v khc vi du qun hnh xon c chdy qun ny c qun thnh nhng bnh rng dy phng cch nhau bng nhng rnh h. Bngcch hon vc bit trong khi qun, cc bnh dy c ni tip lin tc m khng cn mi hn giachng. Dy qun loi ny dng lm cun cao p cho in p t 35kV trln v c dung lng ln. Dy qun xen k.

Cc bnh dy cao p v h p ln lt c qun xen k nhau dc theo tr thp. Kiu dy qunny thng dng trong cc my bin p kiu bc.2.3. V my.

Bao gm thng my v np my. C chc nng bo v li st v cc cun dy. Ngoi ra cngdng ca np thng cn l a u dy vo v a cc u dy ra. V my lm nhim v tn nhit,dp h quang do cu to kn cha du lm nhim vcch in.

a) Thng my bin p: thng lm bng thp, thng l hnh bu dc. Lc my bin p lmvic, mt phn nng lng b tiu hao v tora di dng nhit nng lm nng dy qun, li thp vcc b phn khc. Do , gia my bin p v mi trng xung quanh c mt hiu s nhit v gil chnh nhit. Nu chnh nhit vt qu mc quy nh s lm gim tui thcch in vgy s c vi my bin p. m bo cho my bin p vn hnh vi ti lin tc trong thi gianquy nh v khng b s c phi tng cng lm lnh bng cch ngm bin p trong thng du.Ngoi ra, du my bin p cn lm nhim vtng cng cch in.

b) Np thng: dng y thng v trn t cc chi tit my quan trng nh :

- Cc ca ra ca dy qun CA v HA: lm nhim vcch in gia dy dn vi v my.- Bnh gin du: l mt thng hnh tr, bng thp t trn np v ni vi thng bng 1 ng dn du.- ng bo him: lm bng thp, thng l hnh tr nghing. Mt u ni vi thng, mt u bt bnga thu tinh.

3. Nguyn l lm vic.

My bin p lm vic theo nguyn l cm ng in t:d

edt


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My bin p trn hnh v l my bin p mt pha hai dy qun. Dy qun s cp c N1 vngdy v dy qun th cp c N2 vng dy. C hai cun dy c qun trn mt li st. Li st ccu to t nhiu l thp k thut in. Khi t mt in p xoay chiu U1 vo 2 u ca cun dy scp th trong lng ca cun dy s xut hin mt t thng bin thin vi tn s bng tn s ca dngin trong cun s cp. T thng ny mc vng vi c 2 cun dy 1 v 2. N sinh ra s cm ngv trn cc cun dy s cp v th cp. Khi ni 2 u ca cun dy s cp vi ti n s sinh ra hiuin thU2 v dng in I2 trn ti. Nh vy nng lng ca dng in xoay chiu c chuynt cun dy s cp sang cun dy th cp.

Gi sin p xoay chiu t vo 2 u ca cun s cp l mt in p hnh sin th t thng nsinh ra cng l mt hm s hnh sin: sinm t

Theo nh lut cm ng in t, s cm ng sinh ra trong cc dy qun s cp v th cp sln lt l:

1 1 1 1 1

sincos 2 sin( )

2

mm

d wtde N N N w wt E wt

dt dt

2 2 2 2 2

sincos 2 sin( )

2

mm

d wtde N N N w wt E wt

dt dt

Trong :

1 1

1 1

24.44

2 2

m mm

wN fN E fN

2 2

2 2

24.44

2 2

m mm

wN fN E fN

l gi tr hiu dng ca cc s dy qun s cp v th cp.T cc biu thc trn ta thy s cm ng trong dy qun chm pha so vi t thng sinh ra n

mt gc2

.

H s my bin p: ngi ta nh ngha h s my bin p l t s gia cc i lng sau:1 1 1

2 2 2

E w U

k E w U Nu N2 > N1 => U2 > U1 : gi l my bin p tng p.Nu N2 < N1 => U2 < U1 : gi l my bin p h p.

III. MY IN KHNG NG B1. Khi nim chung.1.1. nh ngha.

My in khng ng bl my in xoay chiu, lm vic theo nguyn l cm ng in t, ctc ca roto n khc vi tc ttrng quay trong my n1. Cng nh cc my in quay khc,my in khng ng b c tnh thun nghch, ngha l c th lm vic 2 chng c v mypht.1.2. Cng dng.

My pht in khng ng bc c tnh lm vic khng c tt nn t c dng, ta ch yuxt ti ng c khng ng b. N c s dng nhiu trong sn xut v sinh hot v ch to ngin, gi thnh r, tin cy cao, vn hnh n gin, hiu sut cao. Gn y do k thut in t phttrin nn ng c khng ng b p ng c yu cu iu chnh tc nn n cng c sdng rng ri hn. Dy cng sut rt rng, tvi W n hng ngn kW.1.3. Phn loi.

My in khng ng b c nhiu loi c phn theo thnh nhiu cch khc nhau.


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Theo kt cu ca v, my in khng ng b chia thnh cc kiu chnh: kiu h, kiu bo v,kiu kn, kiu phng n

Theo kt cu ca rto: rto kiu dy qun, rto kiu lng sc.Theo s pha trn dy qun stato c th chia lm loi: 1 pha, 2 pha, 3 pha.

1.4. Mt si lng nh mc.- Cng sut c c ch trn trc Pm.- in p v dng in dy stato U1m, I1m.- Tn sdng in stato f.- Tc quay rto nm.- H s cng sut cosm.- Hiu sut m.

2. Cu to.Ging nh nhng my in quay khc, my in khng ng b gm nhng phn chnh nh

sau:

2.1. Stato(phn tnh): gm hai b phn chnh l li thp v dy qun, ngoi ra cn c v my vnp my.

- Li thp: c p trong v, lm nhim v dn t. Li thp stato hnh tr do cc l thp k

thut in c dp dnh bn trong ghp li vi nhau thnh cc rnh theo hng trc. V ttrngi qua li thp l ttrng quay nn gim tn hao li thp.

- Dy qun: lm bng dy bc cch in( dy dn in tv c t trong rnh ca li thp),kiu dy qun hnh dng v cch b tr sc trnh by trong phn c sthit k dy qun statong c khng ng b.

- V my: lm bng nhm hoc gang, dng cnh li thp v dy qun cng nh cnhmy trn b, khng dng lm mch dn t. i vi my c cng sut tng i ln (1000kW)thng dng thp tm hn li thnh v. Hai u v c np my v trc. V v np my dng bo v my.2.2. Rto(phn quay): gm c li thp, dy qun v trc my.

- Li thp: ni chung, li thp vn lm bng l thp k thut in nh stato. Li thp c p

trc tip ln trc my.- Dy qun: c hai loi chnh l rto lng sc v rto dy qun.+ Rto dy qun: ging nh dy qun stato. Trong my in ctrung bnh trln thng dng

lm dy qun kiu sng hai lp v bt c nhng u ni, kt cu dy ni cht ch. Trong my incnhthng dng lm dy qun ng tm mt lp. Dy qun 3 pha ca rto thng u hnh sao,cn 3 u kia c ni vo 3 rnh trt thng lm bng ng cnh mt u u trc, v thngqua chi than c thu vi mch in bn ngoi. c im ca loi ng c rto kiu dy qun nyl: c th thng qua chi than a in trph hay sut in ng ph vo mch in rto ci


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thin tnh nng m my, iu chnh tc hoc ci thin cng sut ca my. Khi my lm vic bnhthng dy qun rto c ni ngn mch.

+ Rto lng sc: kt cu ca loi dy ny rt khc so vi dy qun stato. Trong mi rnh ca lithp, rto t vo thanh dn bng ng hay nhm di ra khi li thp v c ni tt hai u bnghai vnh ngn mch bng ng hay nhm thnh ci lng, ngi ta hay gi l lng sc.

cc my cng sut nh, lng sc c ch to bng cch c nhm vo cc rnh li thp rtoto thnh thanh nhm, hai u c vng ngn mch v cnh qut lm mt. Dy qun rto lng sckhng cn cch in vi li thp. ci thin tnh nng mmy trong cng sut tng i ln, rnhrto c th lm thnh rnh su hoc lm thnh hai rnh.

Trong my in cnh, rnh rto thng lm rnh cho i qua mt gc so vi tm trc.ng c lng sc l ng c rt ph bin do gi thnh r v lm vic bo m. ng c dy

qun c u im v mmy v iu chnh tc ng c song gi thnh cao v vn hnh km tincy hn rto lng sc nn chc dng khi ng c rto lng sc khng p ng c yu cu vtruyn ng.2.3. Khe h.

V rto l mt khi trn nn khe hu, khe h trong my in khng ng b rt nh(0,2 1mm trong cc my in cnh v va) hn ch dng in t ho ly t li in v nh vymi c th nng cao h s cng sut ca my.

3. Nguyn l lm vic.Khi c dng in ba pha chy trong dy qun stato th trong khe hkhng kh xut hin t

trng quay vi tc ng b n1=60f1/p (f: tn sli in, p: si cc t ca my). Ttrngny qut qua dy qun nhiu pha t ngn mch t trn li thp rto v cm ng trong dy qun sc in ng v dng in. Tthng do dng in ny sinh ra hp vi t thng ca stato thnh tthng tng ca khe h. Dng in trong dy qun tc dng vi t thng khe hsinh ra momen tcdng do c tc dng mt thit vi tc quay n ca rto. Trong nhng phm vi tc khc nhau thch lm vic ca my cng khc nhau. Ta xt tc dng ca chng trong 3 phm vi tc .

H strt ca my : s = (n1n)/n1.

3.1. Rto quay cng chiu ttrng nhng tc n < n1 (0 < s < 1) (a).Gi thit chiu quay n1 ca ttrng khe h v ca rto n nh hnh v. Theo quy tc bn tayphi , xc inh c chiu sc in ng E2 v I2; theo quy tc bn tay tri , xc nh c lc F vmomen M. Ta thy F cng chiu quay ca rto, ngha lin nng a ti stato, thng qua t trng bin i thnh c nng trn trc lm quay rto theo chiu t trng quay n1, nh vy my lmvic chng c in.3.2. Rto quay cng chiu ttrng nhng tc n > n1 (s < 0) (b).

Dng ng c s cp quay rto ca my in khng ng bvt tc ng b n > n1. Lc chiu t trng quay qut qua dy qun rto sngc li, sc in ng v dng in trong dyqun rto cng i chiu nn chiu ca M cng ngc chiu n1, ngha l ngc chiu vi rto, nn


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l momen hm. Nh vy my bin c nng tc dng ln trc ng c in, do ng c s cpko thnh in nng cung cp cho li in, ngha l my lm vic ch my pht in.3.2. Rto quay ngc chiu ttrng n < 0 (s > 1) (c).

V nguyn nhn no m rto ca my in quay ngc chiu ttrng quay, lc ny chiuca sc in ng v momen ging nh chng cin. V momen sinh ra ngc chiu quayvi rto nn c tc dng hm rto li. Trng hp ny my va ly in nng li in vo, valy c nng tng c s cp. Ch lm vic ny gi l chhm in t.

PHN II. THC HNH QUN DYSTATO NG C KHNG NG B

I. DY QUN STATO NG C KHNG NG B.

Dy qun my in quay l b phn chnh thc hin s bin i nng lng c in trong my.C th chia lm 2 loi: dy qun phn cm v dy qun phn ng. Ni dung bi thc hnh ny ta chxt ti dy qun phn ng(stato) ca ng c khng ng b.

1. Mt si lng c trng.Z s rnh statoq s rnh tc dng di mt cc t (s bi dy ca mt nhm bi)y sbc dy qun (tnh t cnh tc dng th nht n cnh tc dng th hai ca cng

mt phn t) bc ccp si cc (c hnh thnh bi mt cun dy hay nhm cun dy v c u dy sao

cho khi c dng in i qua s to c cc cp cc N-S xen k tip nhau trong mt pha)m s phaf tn sdng in

a s mch nhnh song songn tc quay ca ttrngn1 tc u trc

2. Mt scng thc tnh ton.- S rnhca 1 pha di 1 cc t : q = Z/(2mp) [rnh]- Bc cc(khong cch gia 2 cc t lin tip): = Z/(2p) [rnh]- Bc dy qun(khong cch gia 2 cnh tc dng ca 1 phn t) : y = Z/(2p) + [rnh]

Nu = 0 : dy qunbc (y = )Nu < 0: dy qun bc ngn (y < )Nu > 0: dy qun bc di (y > )

- Gc in gia 2 rnh cnh nhau: = p.360/Z [ in]- Vng pha ca dy qun: = q [ in]

3. Phn loi.- Theo s lp trong rnh: dy qun 1 lp(s phn t ca dy qun S=Z/2), dy qun 2 lp(s

phn t ca dy qun S=Z).- Theo s pha: dy qun 1 pha, 2 pha, 3 pha.- Theo bc dy qun: dy qun bc , bc di, bc ngn.- Theo cch ni cc phn t: dy qun xp, dy qun sng.


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- Theo hnh dng phn t dy qun: dy qun ng khun,ng tm, phn tn, tp trung

4. Yu cu.- m bo c s v dng in tng ng vi cng sut in t ca my.- Kt cu dy qun phi n gin.- t tn nguyn vt liu.- Bn c in nhit ha.- Lp rp, sa cha d dng.

5. Qun dy stato ng c khng ng b.5.1. Nhm dy qun v cch phn b cc bi dy.

- C hai loi nhm dy qun thng gp l: dy qun ng tm v dy qun ng khun.

Dy qun ng khun Dy qun ng tma.Nhm cun dy ng tm.

Nhm cun dy ng tm c hnh thnh bi nhiu cun dy c bc cun dy khc nhau v c mc ni tip nhautheo cng mt chiu qun. Cc cnh dy cami cun dy chim cc rnh k cn nhau to thnh cc t.

to hnh nhm cun dy ng tm, ngi ta qun lin tip cc dy dn theocng mt chiu qun ln trn mt b khun c kch thc khc nhau v t ng tm trn cng mttrc qun.

u im ca cch qun dy ny l d lp t cun dy vo stator nhng c nhc im l cc

u cun dy chon ch nhiu hn so vi cch qun khc.Dng nhm cun dy ng tm thngph bin trong cc ng c cng sut nh .b.Nhm cun dy ng khun.

Nhm cun dy ny c cc bc ca dy u bng nhau nn chng c cng mt khun nhhnh. Cc cun dy ny c b tr trn stator cc rnh k tip nhau to thnh cc t.Thngthng bc cun dy trong nhm cun dy ng khun u l bc ngn nn c u im l t tndy, thu gn cc u cun dy . Tuy nhin t yu cu thu gn cc u cun dy, t chon ch thvic lp t b dy qun dng ny phi kh khn hn v tn nhiu thi gian hn so vi nhm ngtm.

- C hai cch b tr dy qun : Tp trung v phn tn. a. Dy qun tp trung:cc bi dy cng mt nhm bi c t vo cc rnh sao cho cc cnh tc

dng th nht ca chng lin tip nhau.b. Dy qun phn tn:dy qun c t u, cnh tc dng thnht ca bi th hai nm ngay saucnh tc dng th hai ca bi th nht.5.2. Cch u dy gia cc nhm cun dy.

Khi thit lp s b dy qun trn ng c 3 pha, cc nhm dy c th u dy to ra cccc t tht hc cc cc t gi tu theo s b tr cc nhm cun dy trong cng mt pha.a. u dy cc nhm cun to ra t cc tht.

Trong cch u ny, cc nhm dy cng mt pha c b tr st nhau v ni dy gia cc nhmsao cho dng in qua cc nhm to thnh cc cc t N-S xen k nhau.c im cc u dy ny c


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s nhm cun trong mt pha bng s i cc. Khi u dy c th p dng quy tc cui-cui, u-u.b. u dy cc nhm cun to thnh cc cc gi.

Khi mun u dy to thnh cc t cc cng du hay cn gi l cc u dy to t cc gi thbuc phi b tr cc nhm cun dy trong cng mt pha phi cch xa nhau t nht mt rnh trng.Khi u dy, p dng quy tc u-cui bng cch ni cui nhm ny vi u nhm k tip th mito thnh cc cc t cng du.

c im ca cch u dy ny c s nhm cun dytrong mt pha bng mt na s i cc vcch u dy ny ch p dng khi 2p>2. Nh bit, ch c thnh phn on dy nm trong rnhstator mi cc thnh phn tc dng to nn momen quay nn ta c th c khi nim mi v si cc nu mt hoc nhiu rnh c cha dy dn mc cng chiu dng in th chng hnh thnhmt cp cc t N-S. Do c th ni tip cc cnh dy li theo mt trt t no sao cho tho mn iu kin khi c dng in i qua th chng c cng mt chiu.

Khi cc cn dy qun ca cng mt pha nm nhng vng khc nhau trn thang my th ta gi l dy qun tp trung. Nu ta th tch nh cc phn t dy qun tp trung v ri u trn thanmy th ta s c dy qun phn tn. Nhng nu ta thc hin bng cch tch i cc phn t v slng t di v trn th ta s c dy qun hai lp.

5.3. Xy dng s dy qun ng c 3 pha.Xc nh cc thng s ca ng c:- Dng dy qun cn thit k.- Tng s rnhZ ca phn stator.- S i cc 2p v cch u dy to cc tht hay cc gi.- Xc nh bc cc t , bc dy qun- Tnh s cnh dy cho mi cc ca mi pha.Tin hnh cc s theo cc bc:- K cc ng song song v nh s tng ng vi s rnh ca rotor- Tri s cnh dy mt cc mt pha mi pha cho phn b u ti cc trc cc t v xc nh

chiu dng in theo chiu u vo.

- Cn c vo dng dy qun v cc u cun dy ni lin cc cnh dy gia cc nhm cun phasao 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 phaC tng t nh trn v cch pha B cng bng lch pha trn.

II. THC HIN QUN DY NG C KHNG NG B 3 PHA.1. Bi tp 1: qun dy ng khun phn tn 1 lp.

Z=24, 2p=4, q=2, y=5, 65 vng/bi1.1. S dy qun.


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1.2. Qu trnh tin hnh.a. Chun b.- Nhn cc dng c thc hnh : ng c (24 rnh), dao tre, dao, li nha,ko, dy ng, khun,cht, - Qun dy c nhn vo li nha chun b vo khun.- Chun b khun.

Khun c lm t hai ming g mng trn c c cc l to thnh mt hnh lc gic c chuvi bng vi chu vi bi dy ta cn qun. Ta lp khun vo my qun dy v t cc cht vo khun nh hnh khun.- Chun b cch in cho rnh.

Dy qun stato phi c cch in vi phn khung thp ca stato. Do cc bi dy c t vocc rnh nn ta cn c lp cch in trong rnh. Cch in trong rnh c cu to bao gm hai lpc dy :

+ Lp cch in 0.3mm: chiu di bng chiu di ca phn mch t cng thm 3cm gp hai uli 1cm phn mp gp pha ngoi ca mch t. Chiu rng cha ht tit din ca rnh.

Kch thc : di 13cm, rng 2.5cm.+ Lp cch in 0.1mm: chiu di bng chiu di lp cch in 0.3 gp hai u. Chiu rngcha ht tit din rnh cng thm hai di bng.

Kch thc: di 11cm, rng 5cm.Ta c th dng cc giy bocng lm lp cch in 0.3 v cc giy bo mng lm lp cch in

0.1( cn c dai tt).Cho vo cc rnh trc lp cch in 0.3(dng dao tre y st vch rnh, cch in phi m

rng bung st vch rnh, khng c thp hn c rnh), cn lp 0.1 khi tin hnh vo dy rnh nomi cho vo.b. Qun dy vo khun.


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Trc khi tin hnh qun dy vo khun to c bi dy phng v gn gng ta cn vutthng dy qun trc khi qun dy vo bi dy. Nu dy cng phng th vic qun dy vo khuncng d lmcho vic lp dy vo my cng nhanh hn nhiu.

Sau khi vut li dy v qun vo li nha, ta bt u qun dy vo khun to cc bi dy. Lp khun vo my quay(ch lp c gi khun). Nht cht vo khun ( theo cng chiu thun tin lc tho ra). Do cht di nn mi ln qun ta c th qun lin lc 3 bi dy lin tip nhaum khng cn tho khun.

Qun dy vo khun cn qun cht, u tay v theo mt chiu nht nh(tt nht l chiu nh du trn khun),khng c lm xc dy, gi cho dy lun thng khng b cong hay tht nt .Nu c ch xchoc tcn bc li(bng ng gen, i vi bi tp ny c th ch cn ni li dokhng tin hnh chy my) v a n ra u ca bi dy khng trong phn dy s nm trongrnh( trnh gy kh khn khi vo dy).

Khi 65 vng th dng li,buc gi cc cnh tc dngca bi,bt tip bi th hai qun vtng t nh vy ta qun c ba bi dy lin nhau. Sau khi qun xong c ba bi dy ta tho khun rakhi my qun dy. Dng dy c nh tng bi li ri tho cc chtly cc bi dy ra khi khun.Ln lt lm nh vy cho n khi 12 bi dy.c. Vo dy.

- Chn mt rnh bt k lm rnh s 1. Theo s dy qun ta s xc nh c cc v tr ca cc

rnh tip theo. C th chn cch vo dy thun hoc ngc chiu kim ng h. - Theo s dy qun mi bi lun c 2 cnh tc dng nm trn v 2 cnh tc dng nm di, vvy i vi 2 bi u tin ta phi tin hnh vo dy nh sau : rnh 2 v 4 c ch. Ly 2 bi dymt bi ta nht 1 cnh vo rnh 2, mt bi ta nht 1 cnh vo rnh 4, 2 cnh cn ca 2 bi chanht ngay.- Cc bi cn li vo trn 1 bi :

+ Nht cnh bi 3 vo cc rnh 1, 6.+ Nht cnh bi 4 vo cc rnh 3, 8.+ Nht cnh bi 12 vo cc rnh 19, 24.

- Cn li 2 cnh ca 2 bi u tin ta vo nt 2 rnh cui cng l 21 v 23.

- Ch :+ Trc khi vo dy rnh no th t sngiy cch in 0.1 vo rnh , p st giy cch in

vo vch rnh, xp giy cch in u v hai bn trnh tnh trng mt bn di mt bn ngn skhng m bo an ton cho vic cch in.

+ Vo cnh no th tho nt buc cnh . Lun gi cnh thng, khng trng, ri. Trc khia dy vo, xi tng vng dy ca cnh tcdng ri ra sp song song( trnh ri) a vo ln lt,dy dvo rnh hn.

+ Khi nht dy vo rnh ta dng dao tre nht. Dao tre phi mng c th a vo trongrnh v cng c th nht c dy. Ch trnh lm qu mnh xccch in ca dy. Ta tmt cnh ca bi dy vo rnh ri dng dao tre vut nh cho dy vo nm ht trong rnh. Sau nhn nh nhng u cho dy nm chc chn trong rnh ri mi tin hnh nht cch in. Phi

m bo sau khi nht cch in th ton b phn giy cch in phi nm gn trong rnh. Cn cni hai u cun dy sau tin hnhnn trnb cong cc u ca bi. Sau khi nht c hai cnh cabi dy vo th ta n phn u ca bi dy xung khng che cc rnh khc, d dng vo cc bidy tip theo.

+ cc u ra u vo ca mi bi gn tm cc u u dy c thun tin. d. Lt pha.

Tin hnh lt pha bng cc ming cch in hnh bn nguyt ti cc u ca bi dy ( c th sdng giy cch in 0.3). Ch chiu cao khng qu mt my, ct va cc bi dy.e. u dy.


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u cui-cui, u-u.Mi bi c hai u dy mt u vo v mt u ra. C 12 bi v 3 phanh vy mi pha c 4 bi dy.

Chn mt u ca mt bi dy bt k quy nh lm pha A. u u cui biA1 vi u cuibiA2, u vo biA2 vi u vo biA3, c nh vy ta u c pha B v pha C. Cnh sau camt pha thng cch cun trc 2 bi dy lin tip.Ba u ra l X, Y, Z.1.3. Kt qu, nhn xt.

Bi tp ny khng yu cu chy my nn khng cn ai dy, mc ch l quenvi cc thit b,thao tc lm vic, tp vo dy, u dy chun b cho bi 2.

2. Bi tp 2 : qun dy ng tm tp trung 1 lp.Z=36, 2p=4, q=3, yTB=9, 75 vng/bi

2.1. S dy qun.

2.2. Qu trnh tin hnh.a. Chun b.

Qu trnh chun b cng tng t nh trong bi tp qun dy ng khun phn tn. Song c 1vi im khc :

-Nhn trc tip ng c qun hon chnh nn :+ Cn quan st ton b ng c chun b cho bi tp ca mnh : cch u dy, ai dy,cch lyu vo u ra,th t cc bi, lt pha, lt cch in

+ Tho dy :- Ct dy ai, tho lt pha.- Ct 6 udy mm( u vo ra cc pha), ct 3 mi ni gia 6 nhm bi. Gi li lt pha, dy mmv cc ng gen( s dng sau).- Tho dy khi rnh : ( ch ngc vi qu trnh vo dy)

+ Chn 3 cnh pha trn ca cng 1 nhm bitho trc. Trong mi nhn tho t bi to ti binh.

+ Tho lp cch in 0.1, tm cc si trn cng ri dn dn a ht cc dy ra khi rnh( trnhlm xc dy v lm hng lp cch in 0.3).


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+ Nhm bi u tin ch tho 3 cnh tc dng nm trn, tip tc tho cc nhm bi cn li (trnc nhm bi), cui cng mi tho nt 3 cnh cn li ca nhm bi u tin. - Sau khi tho dy xong, g v tin hnh qun dy vo li nha nh bi 1 chun b cho qun dyvo khun.

- Khun bi ny gm 18 l cht to thnh 3 hnh lc gic ng tm.

.- Xem li lp cch in 0.3 c sn trong my. Nu khng b rch, vn m bo c cch

in th khng cn thay.b. Qun dy vo khun.

Cc thao tc cng ging bi 1.V dy qun ng tm, ta ln lt qun t bi nh n bi to. Sau khi m 75 vng dy ta

tch dy nht cc v tr cht tip theo tip tc qun bith 2(ch nht cht cng chiu thora c d dng). Tng t cho bi th 3l xong mt nhm 3 bi dy. Tho khun, buc cc cnhca tng bi v c nhm bi, ch trnh o chiu vt ca dy gia cc bi. Trong bi ny c tt c6 nhm bi dy nh vy.

V bi tp c tin hnh chy my nn cch in phi m bo, trnh lm xc dy. i vi ccmi ni t cn co sch lp sn cnh in bn ngoi ri mi ni vo, dng ng gen bc li. Kimtra c cc mi ni c t trc. a cc mi ni trnhv tr cc cnh tc dng( kh vo rnh).c. Vo dy.

- Chn mt rnh rnh 1. Theo s dy qun ta s xc nh c cc v tr ca cc rnh tip

theo. C th chn cch vo dy thun hoc ngc chiu kim ng h. - Ly mt nhm bi a cc cnh tc dng th hai ca chng ln lt vo cc rnh 4,5,6 ( vo

t cnh bi nh ti bi to).- Ly nhm bi th 2 a cc cnh tc dng th nht(cng pha) ca chng vo ln lt t cc

rnh 1,2,3, cc cnh tc dng th 2 ln lt vo cc rnh 10,11,12.- Ly nhm bi th 3 a cc cnh tc dng th nht ca chng vo ln lt t ngoi vo trong

vo cc rnh 7,8,9, cc cnh tc dng th 2 ln lt vo cc rnh 16,17,18.- Ly nhm bi th 6 a cc cnh tc dng th nht ca chng vo ln lt t ngoi vo trong

vo cc rnh 25,26,27 cc cnh tc dng th 2 ln lt vo cc rnh 34,35,36 - Cn li a cc cnh tc dng th nht ca nhm bi u tin xung cc rnh 31,32,33.

-Ngoi cc ch nh phn vo dy bi 1, ta cng cn lu ti :+ Chiu ca dy vt trong bi dy, khng ng chiu d dn n tnh trng trit tiu t trng khimy chy.+ Rnh ca ng c 36 rnh nh hn ng c 24 rnh nn cn kho lo khng cho hai dy chngln nhau dn n kh khn trong vic a dy vo trong rnh v d dn n xc lp cch in .+ t dy vo rnh no th tin hnh nht giy cch in lun vo rnh sau nn trn cc ucun dy thun tin cho vic vo cc cun tip theo v sau ny khng b vng khi lp rto. d. Kim tra thng mch, chm pha, chm v.


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Dng ng h kim tra thng mch ca cc nhm bi, chm pha(gia cc pha vi nhau), vchm v(gia cc pha vi v).e. Lt pha.Tng t bi 1.

Tin hnh dng ba g dy, ng thi nn chnh cho dy qun khng cao qu mt ng c,khng cn tr khi lp rto.f. u dy.

u u-cui, cui-u.Mi pha c 2 nhm bi i in nhau.Tin hnh u dy theo s c, cn ch co sch lp cch in v dy ng. Khi

m bo dn in tt ta bc chng bng ng gen cch in. Khi u my xong th ta xc nh c 6u l A, B, C, X, Y, Z, co sch cc u ri u vi 6 dy mm, ly ng gen bc li(trnh u bidy chm v). Sp xp cc dy vo ra gn gng, nh du d phn bit .

Sau khi u xong ta dng ng h kiu tra lithng mch, chm pha, chm v.g. ai dy.

Dng dy d ai my cho gn gng, gibuc chtcc bi dy, giy cch in v cc mi ni.Sau g li dy, nn chnh li cc bi dy cho tht st xung vnh stato, un dy cho gn gng vtrn p, trnh va qut vi rto. Chnh li cch in trong lng my

Kim tra thng mch, chm pha, chm v ln na trc khi lp rto v chy my. h. Chy my.

Kim tra li ng c v dy qun, cch in, pha, mi niLp rto vcp in,chy my v o kt qu.

2.3. Kt qu, nhn xt.a. Kt qu

Sau khi cp incho ng cv o cc gi tr dng in v in p ta thu c kt qu : Ik = 3.4A IA = 1.15A IB = 1.1A IC = 1.1A UA = UB = UC = 210V n = 1480 vng/ph

b. Nhn xt.- Hon thnh c sn phm.- Dng khi ng ln khi ng ng c.- Dng in gia cc pha cn c sai khc: do qun s vng dy cha chnh xc,do ngn mch mts vng dy do b xc, hng cch in, do sai s thit b o


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KT LUN

Thc tp l mt trong thi gian sinh vin c th hc hi nhiu kinh nghim thc t v cc kinthc c trang b trn ging ng. Vic lm quen vi cc my mc thit b, sinh vin c thtip cn thc t, cng c l thuyt v thc tin to thm kinh nghim c th lm vic sau ny.

t thc tp xng in va qua tht l khong thi gian thc hnh qu bu i vi sinh vinthc tp ni chung v i vi c nhn em ni ring. Qua t thc tp ny em c ci nhn tngqut hn v su sc hn v cc kin thc l thuyt mn hc; ng thi, cng tch ly c nhiukinh nghim cho bn thn, rn luyn tnh cn thn t m, tc phong nhanh nhn khn trng trongcng vic

Hc i i vi hnh s gip sinh vin d hc hn v nm vng kin thc hn, ch ng em hy

vng rng trong qu trnh hc tp ti, chng em s c thc hnh nhiu hn.

Cui cng em xin chn thnh cm n cc thy c tn tnh hng dn chng em hon thnhtt t thc tpva qua.

Sinh vinNguyn Minh Tun

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