khÍ cỤ ĐiÊn

M au:

Bi 1: NHNG KHI NIM C BN V IN

M bi : MD-M3-B1

A-MC TIU THC HIN

- Trnh by cc khi nim, cc i lng trong mch in

- Tip cn vi cc thng s chnh ca mch in

- Nu khi nim v cc thng s chnh trong mch inmt chiu v mch in xoay chiu

B-CC NI DUNG CHNH

- Khi nim v cc i lng in

- Khi nim v mch in

- Cc thnh phn trong mch in

- Ngun in xoay chiu v ngun in mt chiu

C-CC HOT NG HC TP

-Hc v khi nim cc i lng in, cc thng s ca mch in v cc loi dng in s dng trn tu thy trn lp

-Tham kho cc ti liu v mch in. Ni dung ny c hc tp t tc

HOT NG I : NGHE THUYT TRNH C THO LUN

I-Khi nim v cc i lng in

1.1.Khi nim v in p

a.in th

Ti mt im no ca mch in c chn l im gc v c in th bng 0 (im t ) khi in th ca mi im khc trong mch c gi tr m hay dng c mang so vi im gc v c hiu l in th ti im tng ng.

Gi s ti im B so vi gc th th ti im B tng ng l: V

n v o ca in th l vn (V)

b.in p

in p l hiu s in th gia hai im khc nhau ca mch in.

Khi nim in p ny c rt ra t khi nim in th trong vt l.

Vy: in p gia hai im A v B ca mch (K hiu l UAB ) c xc nh bi:

U = V

- V = - U ( 1.1 )

V: in th ti im A so vi gc.

V: in th ti im B so vi gc.

in p c k hiu l U,i lng o l vn (V), kV, MV .v.v.

1.2.Khi nim v dng in

a.Khi nim

Dng in l dng chuyn di c hng ca cc ht mang in tch (Ht mang in tch l cc ht electron mang in tch m).

Dng in trong mch c chiu chuyn ng t ni c in th cao n ni c in th thp v do dng in c chiu ngc vi chiu chuyn ng ca cc ht in t (electron).

K hiu dng in:I

i lng o l Ampe (A)

b.iu kin duy tr dng in

c dng in v duy tr c n th phi c hai iu kin sau:

-Tn ti in p ti hai im.

-Ni hai im c in p vi mch kn.

1.3.Khi nim v in tr

a.Khi nim

in tr l thng s c trng cho s tiu hao nng lng ch yu di dng nhit.

Mc tiu hao nng lng ca in tr c nh gi bng cng sut ca n v xc nh theo cng thc sau:P = U.I = IR ( 1.2 )

P:Cng sut tiu hao nng lng tnh bng Wot (W),

U: in p t vo hai u in tr (V),

I: Dng in chy trong in tr (A),

R: in tr,tnh bng m ( ( ).

b. S ph thuc ca in tr vo vt dn

xc nh c s ph thuc ca in tr vo vt dn ta phi da vo cng thc tnh in tr ca mt on dy dn,cng thc ny l cng thc trong vt l:

R = (. ( 1.3 )

Trong :

R: in tr ca on dy dn,tnh bng (.

(: (R) in tr sut ca vt liu lm in tr.

l: Chiu di on dy dn,tnh bng mm.

s: Tit din ca on dy dn,tnh bng mm.Da vo cng thc ta thy: vt liu c in tr sut (() cng ln th in tr (R) ca n cng ln,tit din dy cng ln th in tr cng nh.

Vy:in tr ph thuc vo 3 yu t sau:

-T l thun vi in tr sut (().

-T l thun vi chiu di (l).

-T l nghch vi tit din (s).

c. in dn

Gi tr nghch o ca in tr R c gi l in dn.

g =

(1.4)n v tnh ca in dn l Simen (S).

1.4.Khi nim v mch in

a.nh ngha

Mch in l tp hp cc thit b in ni vi nhau bi cc dy dn. Cc thit b in v dy dn to thnh nhng vng kn trong dng in chy qua c.

b.V d v mch in

U:ngun in nng,ngun ny c

th l ngun in mt chiu hoc ngun

in xoay chiu tu thuc vo ph ti.

:bng n,

R:in tr.

1.5.Cc thnh phn trong mch in

a.Ngun in

Ngun in l thit b pht ra in nng, v nguyn l th n c bin i t cc dng nng lng nh: c nng, ho nng, nhit nng.v.v.

V d: pin, c quy bin i ho nng thnh in nng, my pht in bin i c nng thnh in nng, pin mt tri bin i nng lng bc x mt tri thnh in nng.

Ngun in c hai loi ngun in nng chnh:

Ngun in mt chiu,

Ngun in xoay chiu.

b.Dy dn

L thit b quan trng trong mch in n gp phn ni t ngun ti ti, ni cc ti vi nhau v c nhim v lm kn mch.

c.Ti (vt tiu th in )

Ti l cc thit b tiu th in nng v bin i in nng thnh cc dng nng lng khc nh c nng, nhit nng, quang nng.v.v.

V d: ng c in tiu th in nng v bin in nng thnh c nng, bp in bin in nng thnh nhit nng, bng in bin in nng thnh quang nng.v.v.

1.6. Ngun in xoay chiu v ngun in mt chiu

Trn tu sng hin nay ngun in xoay chiu c s dng rt rng ri: hoc ly trc tip t my pht in xoay chiu trn tu hoc ly t in trn b khi tu cp bn. Chng ta bit rng ngy nay s pht trin ca thit b bn dn nn tnh nng chnh lu dng in xoay chiu thnh dng in mt chiu rt d dng v n gin. V cu to ca my in xoay chiu v my in mt chiu c gii thiu phn sau. Trong phn ny chng ta ch nghin cu v nhng c im c bn ca dng in xoay chiu v dng in mt chiu.

a. Ngun in mt chiu

Ngun in mt chiu c k hiu hu ht trn cc thit b tiu s dng ngun mt chiu l : DC (Direct Curent) hoc l :-

Cc c trng ca ngun in mt chiu bao gm:

- in p nh mc : Um (V) thng 6V, 12V, 24V.v.v.

- Cng sut nh mc : Pm (W).

- Dng nh mc : Im (A).

- Du cc tnh : Dng (+) v m (-). Mt iu cn ch l trong mch in mt chiu thng dy dng c mu v dy m c mu en. Nhng chng ta cng khng nn tin tng qu v mu ca dy s xc nh ng cc tnh, bi v trong nhiu trng hp ngi ta lp rp mch khng tun theo quy phm.

b. Ngun in xoay chiu

K hiu ngun in nng xoay chiu l : AC (Auto curent) hoc l :

Cc i lng c trng ca ngun in nng xoay chiu bao gm:

- S pha: c th l ngun 1;2 hoc 3 pha,

- in p nh mc : Um (V) thng 110V, 220V hoc 380V .v.v,

- Cng sut ton phn nh mc : Sm (KVA),

- Dng nh mc : Im (A),

- H s cos: thng giao ng t 0,9-0,98,

- Tn s nh mc fm (HZ): y l thng s rt quan trng trong ngun nng lng in xoay chiu. Hin nay cc ngun in nng thng s dng loi tn s : 50HZ hoc 60HZ.

HOT NG II : NGHE GII THIU V XEM TRNH DIN MU (BI NY KHNG CN)

HOT NG III : RN LUYN K NNG (BI NY KHNG CN)D-CU HI NGHIN CU

-Trnh by cc i lng c bn trong mch in

-Trinh by cc i lng chnh trong ngun in mt chiu v ngun in xoay chiu

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : NHNG KHI NIM C BN V MCH IN

M bi : MD-M3-B1

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by v dng in mt chiuTrnh by ng dng v cc i lng c bn

2Trnh by v dng in xoay chiuTrnh by ng dng v cc i lng c bn

Bi 2 : MT S NH LUT C BN CA MCH IN

M bi : MD-M3-B2

A-MC TIU THC HIN

-Trnh by cc nh lut trong mch in

-Trnh by cc mch o lng in c bn thng gp di tu thy

-Pht biu v a ra ng dng ca cc hin tng cm ng in t

-Bit lp rp cc mch o in : o in p, Dng in, in trB-CC NI DUNG CHNH

-nh lut m

-nh lut Jun-Lenx

-Cc mch o lng in c bn

-Hin tng cm ng in t

C-CC HOT NG HC TP


I-nh lut m

1.1.Th nghim

S ph thuc ca cng dng in vo hiu in th : mun c dng in trong mt vt dn th ta phi t vo hai u vt dn mt hiu in th.

Xt s :

Khi kho K m, ta c c U = 0, I = 0,

Khi kho K ng, ta c c U 0, I 0,

Khi tng gim ngun in tc l U thay i th I thay i theo. Vy cng dng in t l thun vi in p. Gi nguyn in p U nhng ta thay i gi tr in tr ca vt dn th dng in I cng thay i theo. Vy cng dng in ph thuc vo in tr ca vt dn.

1.2.Pht biu nh lut m: Cng dng in trong vt dn t l thun vi hiu in th gia hai u vt dn v t l nghch vi in tr ca vt.

I = ( 2.1 )

T cng thc trn ta suy ra

U = I.R

R =

(2.2)Nu in th U tnh bng vn ( V ), cng dng in tnh bng ampe (A) th in tr R tnh bng m ( ).

1 = 1 (2.3)1 m l in tr ca mt dy dn khi gia hai u dy c hiu in th 1 vn th to ra dng in c cng 1 ampe.

1k = 1000

1M = 1000000

1.3.ng dng nh lut m cho on mch c n in tr

a.nh lut m ng dng cho on mch c n in tr mc ni tip

Cng dng in:

I = I1 = I2 = I3 = . = In ( 2.4 )

Hiu in th:

U = U1 + U2 + U3 + + Un ( 2.5 )

in tr tng ng:

R = R1 + R2 + R3 + . + Rn ( 2.6 )

b.nh lut m ng dng cho on mch c n in tr mc song songCng dng in:

I = I1 + I2 + I3 + . + In (2.7 )

Hiu in th:

U = U1 = U2 = U3 = = Un ( 2.8 )

ien tr tng ng:

( 2.9 )

II-nh lut Jun - LenxDng in tch chuyn ng trong vt dn lm va chm vi cc phn t trong vt dn v truyn nng lng cho cc phn t t lm tng s chuyn ng nhit trong vt dn. Qu trnh ny l qu trnh chuyn ho t in nng sang dng nhit nng hay ni cch khc l dng in c tc dng nhit. Tc dng nhit ca dng in c ng dng rt rng ri trong thc t nh bn i, bp in ..

hiu su hn v tnh cht nhit ca dng in ta nghin cu nh lut Jun Lenx.2.1.Th nghim

S tng nhit ca bnh nhit lng k cha nc do tc dng nhit ca dng in chy trong dy in tr thun nhng trong nc ta c th o c nhit do dy dn to ra. Cho mt trong ba i lng I, R, t thay i v gi c nh hai i lng cn li ta thy:Q ~ I

H-2.4

Q ~ R ( 2.10 )

2.2.Kt lun

Gi Q l nhit lng nhn c t in tr thun R, khi c dng in I chy qua n trong thi gian t v gi A l cng ca dng in sinh ra trong thi gian ta s c quan h:

Q = A

A = U.I.t ( 2.11 )

Q = U.I.t

n v ca Q c tnh bng Jun.

Ta cng c th tnh nhit lng Q theo in tr thun R, cng dng in v thi gian t.

Theo nh lut m ta c:

U = I.R ( 2.12 )

Nhit lng to ra l: Q = IRt ( 2.13 )2.3.Tc dng t ca dng in

Th nghim:

Khi c dng in chy trong dy dn th kim nam chm c ko lch chng t dng in cng gy ra lc t tc dng ln kim nam chm hay ni cch khc l dng n c tc dng t.

T th nghim ta thy tc dng H-2.5

t khng nhng xy ra xung quanh nam chm m xung quanh dy dn c dng in cng c tnh cht tc dng t.

a. Tc dng lc ca dng in

t mt on dy dn c dng in trong t trng th dy dn c lc in t tc dng ln n, chiu ca lc in t c xc nh theo quy tc bn tay tri. hiu su hn v tc dng lc ca dng in th ta s nghin cu cc phn sau ( ng c in ).

b. Tc dng ho hc ca dng in

Tc dng ho hc ca dng in l nhng ng dng ca n: dng in c rt nhiu tc dng ho hc c th nh : m in, pin .

- M in: y l phng php dng dng in ph ln cc vt mt lp kim loi khng r nh kim, vng, bc

Mun m mt vt no , lm sch b mt cn m ri nhng vo bnh in phn lm thnh cc m. Cc dng l thi kim loi ca lp m ( nh kim, bc, vng . ). Dung dch in phn l mt mui tan ca kim loi m, khi dng in qua dung dch mt lp kim loi m s ph kn b mt cn m cn cc dng b mn dn.

- Pin: pin l loi bin i ho nng thnh in nng ( chng trnh sau ta i su nghin cu v c quy axit mt ng dng quan trng v rng ri ).

III-Cc mch o lng in

3.1.o dng in

a.S

o c dng in trong mch ta dng ng h Ampe k mc ni tip vi mch cn o.

b.Phng php m rng gii hn thang o ca Ampek

Dng in tr ph mc song song vi ng h Ampek m rng thang o, in tr ny thng k hiu l R. in tr R c tr s bit trc v c nh, khi bit in p t vo mch v ta tnh c dng qua in tr khi tr s dng ca mch bng tng tr s dng qua Ampek v tr s dng qua in tr R

I = I + I ( 2.14 )

I:dng in ca ton mch.

I:tr s dng o c Ampek.

I:tr s dng qua in tr R.

Thng R mc ngay bn trong ng h, nu tr s dng trong mch qu ln (da vo in p v ti) th ta nhn thy ng h Ampek khng o c v vy phi mc thm in tr ph na vo mch.

3.2.o in p

a.S

Dng c o in p l ng h Vn k. o c in p trong mch ta dng ng h vn k mc song song vi mch cn o.

Dng ng h vn k mc song song vi mch, nu mc ng h vn trong mch in mt chiu ta dng loi ng h vn k kiu t in v phi ch n du cc.

b.Phng php m rng gii hn o ca vn k

Da vo nh lut m p dng cho on mch ni tip, in p mch bng tng in p ri trn cc phn t mc ni tip. m rng thang o ta mc ni tip vi ng h vn k mt in tr ph R

Vy ta c :

in p trn R l U

in p trn vn k l U

in p mch l U

Suy ra:

U = U + U (2.15 )

Trong R c gi tr c nh

Thc t trong vn k c R di o rng, ta ch ni thm in tr ph vo khi no ngun p qu ln.

3.3.o cng sut

a.o cng sut trong mch in xoay chiu

Phng php o ny l dng ng h Wot k, c tr s l ta bit c cng sut ca mch.

ng h Wot k c 4 u dy u vo mch, trong :

C hai u l cun p ca Wot k mc song song vi ti. Cun ny cn c gi l cun ng.

C hai u l cun dng ca Wot k mc ni tip vi ti.Cun ny cn c gi l cun tnh.

Dng phng php o trc tip ny khi

ta c sn ng h Wot k.

b.o cng sut trong mch in mt chiu

Phng php ny ch dng khi o cng sut mch in mt chiu, ta c trong tay 2 ng h ( vn k v ampe k ).

Da vo cng thc tnh cng sut :

P = U.I ( 2.16 )

Mc ng h vn k song song vi ti v mc ng h ampe k ni tip vi ti, ly hai ch s trn hai ng h v dng php nhn l ta bit c cng sut ca mch cn o.

3.4.o in tr

a.m k

C: c cu o kiu t in,

N: nt n thng m,

(: ngun in mt chiu (pin),

R: in tr hn ch trong mch,

R: in tr cn o.

Trc khi o ta n nt N kim tra xem ng h cn hot ng tt hay khng: Nu kim ch quay v ht mt chia th ng h cn hot ng tt.

Ni hai cc ca ng h vo hai u in tr cn o, sau c trn thang ng h th ta bit c tr s ca in tr R.

b.Gii thch:

I = ( 2.17)

Rc: in tr ca ng h C,

M gc quay ca ng h: = s.I,

s: nhy ca ng h, n ph thuc vo phn c kh ca ng h,

Do ( R + R ) khng i, s v cng khng i.

Nn R = - ( R + R )

= - ( R + R ) ( 2.18 )IV-Hin tng in t

4.1.nh lut cm ng in t

a.Th nghim v hin tng

Tin hnh th nghim: ni hai u ca cun dy vi in k sau a mt nam chm vnh cu vo trong lng cun dy. Trong qu trnh nam chm di chuyn trong lng cun dy th kim in k b lch, iu chng t c sc in ng v dng in trong cun dy. Khi nam chm ng yn th in k li ch gi tr 0. Nu ko nam chm theo chiu ra khi cun dy th kim in k li lch nhng ngc so vi ban u.

b.Kt lun

Qua th nghim ny chng t y chnh l hin tng cm ng in t, khi t thng qua cun dy bin thin th trong cun dy xut hin mt sc in ng v c gi l sc in ng cm ng. Sc in ng cm ng ch xut hin khi t thng bin thin, chiu ca n ph thuc vo chiu bin thin ca t thng.

hiu r v s xut hin sc in ng cm ng ta xt mt dy dn thng chuyn ng trong t trng u (B) c vn tc khng i theo phng vung gc vi ng sc t l (v) . Trong dy dn c cc in t t do, khi dy dn chuyn ng cc in t t do cng chuyn ng theo. S chuyn ng ca cc in t to thnh dng in ngc chiu vi phng chuyn ng ca cc in t. Chiu ca sc in ng cm ng xc nh theo quy tc bn tay phi:

t lng bn tay phi hng vung gc vi cc ng cm ng t (B), chiu choi ra ca ngn tay ci l chiu chuyn ng ca thanh dn, chiu t c tay n ngn tay l chiu ca sc in ng cm ng. Nhn vo s H-2.2.

c.ng dng ca hin tng cm ng in t

Hin tng cm ng in t c ng dng rt rng ri c bit l trong loi in nng xoay chiu nh : my bin p, my pht in, ng c in .. Tt c cc ng dng ny ta s hc cc chng sau ny.

My pht in l ng dng ca hin tng cm ng in t, khung dy chuyn ng trong t trng sinh ra mt sc in ng cm ng, ni hai u ca khung dy vi mch ngoi ta c mt in p cm ng. Dng in cm ng xut hin khi hai u mch ngoi c ni vi ti.

Sc in ng cm ng c chiu xc nh theo quy tc bn tay phi, nh vy c nng trong trng hp ny bin thnh in nng. y l nguyn l c bn ca tt c cc loi my pht in.

4.2.nh lut lc in t: Ngc li vi ng dng ca my pht in l ng dng ca ng c in, trong trng hp ny th in nng c bin i thnh c nng. Khi ta a dng in vo khung dy ni kn mch t trong t trng, khung dy s chu mt lc in t, lc in t ny c xc nh theo quy tc bn tay tri.

Quy tc bn tay tri: t lng bn tay tri hng vung gc vi cc ng cm ng t, chiu t c tay n ngn tay l chiu ca dng in, chiu choi ra ca ngn tay ci l chiu ca lc in t . Hai thanh tc dng ca khung dy chu tc dng ca cp ngu lc in t ( Hai lc cng phng, cng ln nhng ngc chiu ), cp ngu lc ny sinh ra m men lm quay khung dy. y l nguyn l ca tt c cc loi ng c m sau ny ta nghin cu.

HOT NG II : NGHE GII THIU V XEM TRNH DIN MU-Xem li s u dy cc mch o-Thuyt trnh li th nghim v nh lut m v nh lut Jun-Lenx

-Trnh by v thuyt trnh li th nghim v hin tng cm ng in t

HOT NG III : RN LUYN K NNG

TTCc hot ngDng cYu cu ca hot ng

1Th nghim v nh lut Jun-LenxNgun in, nhit k, in tr t nng v cc thit b ph trLp rp li hon chnh th nghim ri tin hnh thc hin

2Th nghim v hin tng cm ng in tng dy, nam chm vnh cu, ng h mV v dy inLp rp li hon chnh th nghim ri tin hnh thc hin

3Lp rp v o cc i lng in : Vn, ampe, Cng sut mch mt chiu, cng sut mch xoay chiuNgun mt chiu, ngun xoay chiu, in tr t nng, Vn k, Ampe k, Watt k v cc dy dn inLp rp li hon chnh th nghim ri tin hnh o cc i lng in

D-CU HI NGHIN CU

-Trnh by ng dng ca nh lut m-Trnh by ng dng ca nh lut Jun-Lenx

-Trnh by cc ng dng ca hin tng cm ng in t

-Nu phng php o cng sut trong mch in mt chiu v mch in xoay chiu

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : MT S NH LUT C BN CA MCH INM bi : MD-M3-B2H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Hin tng cm ng in t c ng dng g?Nu ra cc ng dng nh : ch to my pht in, ch to ng c in, ch to cc kh c in v.v.

2Trnh by s khc nhau v o cng sut trong mch in mt chiu v mch in xoay chiuMch mt chiu o gin tip. Mch xoay chiu o trc tip

Bi 3 : THIT B IU KHIN V BO V

M bi : MD-M3-B3

A-MC TIU THC HIN

-Trnh by v cu to v nguyn l hot ng ca cc thit b iu khin v bo v trong mch in

-Nu ra ng dng ca tng thit b bo v trong cc mch in

-Lp rp, vn hnh cc mch o, iu khim v mch bo v

B-CC NI DUNG CHNH

-Cng tc in-Nt n-Aptomat-R-le trung gian-R-le thi gian-R-le dng in-R-le in p-R-le nhit-Cu ch-Cng tc t

C-CC HOT NG HC TP


I-Cng tc

1.1.Khi nim

Cng tc l mt loi kh c ng ngt dng in bng tay, c hai hoc nhiu trng thi n nh, dng chuyn i, ng ngt mch in c cng sut nh, c in p mt chiu n 440V, in p xoay chiu n 500V. Cng tc c b tr trong mt hp kn m bo cc yu cu v cch in, chng m, chng du. Cng tc thng c dng chuyn mch tn hiu iu khin, tn hiu o, ng ngt cc thit b cng sut nh nh thit b chiu sng, bp in, thit b in sinh hot, Cng tc in c b tr c cu l xo nn vic ng ct xy ra nhanh v dt khot, hn ch c h quang.

1.2.Phn loi

Theo s pha:

Cng tc mt pha

Cng tc ba pha.

Theo phng thc tc ng:

Cng tc n: tc ng bng tay, ch c 2 v tr tc ng ng/ngt.

Cng tc gt: tc ng bng tay, c th c 2 hoc 3 v tr tc ng.

Cng tc xoay: tc ng bng tay, c th c nhiu v tr tc ng.

Cng tc hnh trnh: c s dng cm bin v tr v t ng tc ng, thng c 2 v tr, nhng mt s loi c 3 v tr.

Cu to

Ni chung mt cng tc c cc b phn chnh sau:

Tip im tnh.

Tip im ng.

C cu tc ng: chuyn trng thi tip im.

V bo v.

Loi cng tc n c cu to n gin, c hai trng thi ng/ngt v thng c 1 cp tip im, cng tc ny thng c s dng ng ngt cc thit b in cng sut nh nh n chiu sng, hoc cp tn hiu n iu khin mt thit b in.

Hnh 3-1a) l s cu trc ca mt cng tc xoay c 3 v tr tng ng 3 tng tip im. Hnh 8-1b) v tip im tng th nht ng. Hnh 8-1c) v tip im tng th 3 ng.

Hnh 3-1d) l mt cng tc xoay 6 v tr, v tr 0 v 5 v tr iu khin 1, 2, .., 5 tng ng c 5 cp tip im 1-2, 3-4, 5-6, 7-8, 9-10. T s chuyn mch ta c v tr 0 tt c cc tip im u ngt, v tr 1 ch c tip im 1-2 ng, v tr 2 ch c tip im 5-6 ng,

d)

Hnh 3-1. Cu to cng tc xoay

a) S tng th; b) Trng thi tip im khi ng

c) Trng thi tip im khi m; d) Cng tc xoay 6 v tr

Hnh 3-2 v cu to ca mt s loi cng tc hnh trnh, loi cng tc ny c s dng tc ng iu khin hoc bo v khi mt c cu c kh ca mt thit b chuyn ng n gii hn cho php. Chng hn trong h thng li tu thy, yu cu bnh li ch c php quay mt gc 350 tri hoc phi, khi bnh li t n gii hn ny, cng tc hnh trnh s tc ng ngt tn hiu iu khin v bnh li khng th quay hn c na.

1- Tip im ng 2- Tip im tnh 3- C cu tc ng 4- L xo hon nguyn

Hnh 3-2. Cu to cng tc hnh trnh: a) Loi gt; b); Loi n; c) Loi gt hoc n

Hnh 3-3. K hiu tip im cng tc:

a) Cng tc n,

b) Cng tc hnh trnh;

1.3.Nguyn l hot ng

Vi cng tc n v cng tc gt c 2 trng thi, khi c tc ng (bng tay hoc c kh) th cc tip im ca cng tc thay i trng thi, c ngha l tip im thng m th ng li, tip im thng ng th m ra. Loi cng tc thng gp l cng tc n chiu sng s dng trong bung , tng nh cng tc n in nh.

Vi cng tc xoay, thng c nhiu v tr, khi tc ng xoay cng tc th trng thi tip im s thay i tng ng vi v tr cng tc.

Chng hn mt cng tc xoay c bng trng thi tip im nh hnh v, cng tc c 5 v tr, v tr 0 gia v 2 v tr mi bn. Cc cc vo l X, Y, Z, U; cc cc ra l X, Y, Z, U. Khi cng tc v tr 0, X ni vi X; khi cng tc v tr 1 (tri), Y ni vi Y; khi cng tc v tr 2 (tri), Z ni vi Z v U ni vi U;

1.4. Cc thng s k thut c bn

in p nh mc Um: l in p lm vic lu di ca mch in m cng tc khng ch, in p nh mc c th l 110V, 220V, 440V mt chiu v 127V, 220V, 380V, 500V xoay chiu.

Dng in nh mc Im: dng in di hn qua tip im ca cng tc m khng lm hng tip im.

Tui th c kh: c tnh bng s ln ng ngt, thng vo khong 1 triu ln ng ngt khng in v 200 ngn ln ng ngt c dng nh mc.

in p cch in: in p th cch in.

II-Nt n

2.1.Khi nim

Nt n l mt loi kh c in dng chuyn i, ng ngt t xa cc thit b in c cng sut nh vi in p mt chiu n 440V v xoay chiu n 500V.

2.2.Phn loi

a.Theo cu trc

Loi h: s dng trong phng , cu lc b, hnh lang.

Kn: s dng trong bung my.

Chng n: s dng trong cc hm bm trn tu du.

Kn nc: s dng ngoi tri (thit b iu khin neo, ti qun dy, )

C n bo: n bo trng thi ca thit b c iu khin bi nt n.

b.Theo s cp tip im: thng thng nt n c mt n hai cp tip im.

Mt cp tip im

Hai cp tip im

2.3.Cu to

a.Tip im tnh.

b.Tip im ng.

c.C cu tc ng: chuyn trng thi tip im.

d.V bo v.

2.4.Nguyn l hot ng

Nt n c c tnh t hon nguyn, c ngha l khi tc ng, cc tip im ca nt n thay i trng thi, khi ngng tc ng th cc tip im t tr v trng thi c.

Loi nt n c cht ci (k hiu hnh c) th c th s dng nh nt n bnh thng (t hon nguyn) hoc s dng ch ci. Sau khi tc ng, cc tip im thay i trng thi, nu ngng tc ng th cc tip im t tr v trng thi c, nhng nu thc hin ci (thng s dng thao tc xoay nm n) th cc tip im vn trng thi mi cho n khi c tc ng ngng ci.

a) Cu to nt n:

Phm n

L xo hi trng thi (hon nguyn)

Tip im ng

L xo nn tip im

Tip im tnh (thng ng)

Tip im tnh (thng m)

b) Cc loi tip im ca nt n:

1- Tip im thng m

2- Tip im thng ng

3- Cp thng m v thng ng

c) K hiu nt n:

1) Nt n c tip im thng m

2) Nt n c tip im thng ng

3) Nt n c cht ci

Hnh- 3.4. Nt n

2.5.Cc thng s k thut c bn

in p nh mc Um: in p lm vic lu di ca mch in m nt n khng ch, in p nh mc c th l 110V, 220V, 440V mt chiu v 127V, 220V, 380V, 500V xoay chiu.

Dng in nh mc Im: dng in di hn qua tip im ca nt n m khng lm hng tip im.

Tui th c kh: c tnh bng s ln ng ngt, thng vo khong 1 triu ln ng ngt khng in v 200 ngn ln ng ngt c dng nh mc.


III-Cng tc t

3.1.Khi nim

Cng tc t l mt thit b in dng ng ngt t xa cc mch in c in p n 500V, dng in n 600A.

3.2.Phn loi

C nhiu cch phn loi cng tc t,

Phn loi theo nguyn l truyn ng: Cng tc t kiu in t, cng tc t kiu kh nn, cng tc t kiu thy lc.

Phn loi theo dng in qua tip im chnh: cng tc t mt chiu & cng tc t xoay chiu.

Phn loi theo in p cp cho cun ht: cun ht mt chiu & cun ht xoay chiu.

Phn loi theo s lng tip im chnh, tip im ph: 1 tip im chnh, 2 tip im chnh 3 tip im chnh, 4 tip im chnh,

Thng thng trn tu thy s dng cng tc t kiu in t xoay chiu c 3 cp tip im chnh, 2 n 6 cp tip im ph.

3.3.Cu to

Cng tc t in t c cc b phn chnh sau: tip im, mch t, cun ht, hp dp h quang, v

a) Cu to cng tc t:

Cun ht

Mch t tnh

Mch t ng

Tip im ng

Tip im tnh

L xo

b) Nguyn l hot ng:

1- Cun ht in t

2- Mch t ng

3- Tip im chnh

4- Tip im ph

5- C cu lai h thng tip im

6- L xo chng dnh

c) Hp dp h quang:

1. Tip im tnh

2. Tip im ng

3. Cun dy thi t

4. Bung dp h quang

5. Vch ngn

d) Cc c cu tc ng

Hnh -3.5. Cng tc t

Cng tc t thng c 3 n 4 tip im chnh (ng ngt mch ng lc) v mt vi cp tip im ph (ng ngt mch iu khin). Cc tip im ca cng tc t c ch to bng ng v b mt tip xc thng c m bc. tng nn gia tip im tnh v tip im ng, trn mi tip im ng c b tr mt l xo (l xo ny khng c minh ha trn hnh v).

Mch t gm hai phn: phn tnh thng c dng ch E, trn tr gia c t cun ht. Phn ng thng c dng ch E hoc ch I. Phn ng lin k c kh vi tip im ng. Khi phn ng chuyn ng, tip im ng chuyn ng lm thay i trng thi ca tip im nh c minh ha hnh b).

Cun ht c th l mt chiu hoc xoay chiu. Cun ht mt chiu th mch t ca n c lm bng st t mm v li thp t b nng so vi cng tc t xoay chiu. Cun ht xoay chiu th mch t c ghp li t cc l thp k thut in (thp c pha 2% silic) mng hn ch tc ng ca dng xoy Fu-c. Trong mch t cun ht xoay chiu c b tr vng ngn mch chng rung.

Hp dp h quang bao gm cun dy thi t hp vch ngn. Cun dy ny gm mt vi cng dy li khng kh mc ni tip vi tip im v t gn tip im c h quang sao cho t trng do cun dy to ra vung gc vi dng in h quang (Hnh -3.5c). Khi tip im m ra, dng mt t ngt sinh ra sc in ng cm ng to dng cm ng phng qua khng gian gia hai tip im to h quang in. Dng in qua cun thi t s to t trng tc ng vo dng in h quang y h quang vo cc khe h gia cc vch ngn, h quang b chia nh v ko di s t tt.

3.4. Nguyn l hot ng

Nguyn l hot ng ca cng tc t nh sau (hnh b): khi cun dy 1 khng c in, l xo 6 ko tip im trng thi OFF, cc tip im thng m th m ra, cc tip im thng ng th ng li. Khi cp in cho cun dy, tm ng 2 c ht vo ko theo cc tip im, cc tip im chuyn sang trng thi ON, cc tip im thng m th ng li, cc tip im thng ng th m ra.

Cc thng s c bn

in p nh mc Um: in p lm vic lu di ca mch in m nt n khng ch, in p nh mc c th l 110V, 220V, 440V mt chiu v 127V, 220V, 380V, 500V xoay chiu.

Dng in nh mc Im: dng in di hn qua tip im ca nt n m khng lm hng tip im.

Tui th c kh: c tnh bng s ln ng ngt, thng l 10 20 triu ln ng ngt khng in, v 3 triu ln ng ngt c dng nh mc.


Tnh n nh lc in ng: tip im chnh cho php mt dng in ln nht i qua m lc in khng lm thay i trng thi ca cc tip im d trong mt thi gian ngn. Thng qui nh ly dng in th bng 10 ln dng nh mc.

Tnh n nh nhit: khi c dng in ngn mch chy qua trong mt khong thi gian cho php, cc tip im khng b h hng.

IV- R-le in t

4.1.Cu to

R-le in t c cc b phn chnh l mch t, cun dy, tip im, v. Mch t c ch to t vt liu st t gm hai phn, phn tnh hnh ch U v phn ng l tm thp hnh ch I. Phn ng ni lin kt c kh vi tip im ng.

im khc bit c bn gia r-le in t v cng tc t l r-le in t ch c mt loi tip im iu khin c th l thng ng hoc thng m, khng c hp dp h quang, v khng c l xo nn tip im m s dng thanh ng lai tip im to lc nn.

Hnh -3.6. Cu to ca r-le in t.

Cun ht

Mch t

Tm ng

L xo

Tip im ng

Tip im tnh thng ng

Tip im tnh thng m

u ni dy cun ht

4.2.Phn loi

Theo cun ht: cun ht 1 chiu & cun ht xoay chiu.

Theo dng in qua tip im: r-le m chiu, r-le xoay chiu.

Theo s lng cp tip im: 2 cp tip im, 3 cp tip im,

Theo cu trc chn: chn trn, chn dt.

Theo cm r-le: trn, vung.

4.3.Nguyn l hot ng

Khi c dng in chy qua cun dy s sinh ra lc ht in t ht tm ng v pha li. Lc ht in t c gi tr t l thun vi bnh phng dng in v t l nghch vi khong cch khe h mch t:

Khi dng in trong cun dy nh hn dng tc ng i < It th lc ht in t nh hn lc ko l xo F < Flx, tm ng ng yn. Khi i > It th lc ht in t ln hn lc ko l xo F > Flx, tm ng b ht v pha lm cho khe h mch t nh nht, tc l ht v pha phn tnh. Khi khe h mch t nh, lc ht cng tng, tm ng c ht dt khot v pha phn tnh v tip im ng c ng vo tip im tnh.

Khi dng in trong cun dy gim i < it lc l xo s thng lc ht in t. L xo ko tm ng ra khi phn tnh, khe h mch t tng, lc in t cng gim, l xo ko dt khot tm ng v, tip im ng ri khi tip im tnh.

4.4.Cc thng s c bn

in p nh mc cun ht: l in p cp cho cun ht lm vic ch lu di. in p ny c th l mt chiu 9V, 12V, 24V, 110V, 220V, 440V, v 24V, 110V, 220V, 440V xoay chiu. in p ny ghi trn cun ht.

in p nh mc Um: in p lm vic lu di ca mch in m r-le khng ch, in p nh mc c th l 24V, 110V, 220V, 440V mt chiu v 24V, 110V, 127V, 220V, 380V, 500V xoay chiu.

Dng in nh mc Im: dng in di hn qua tip im ca r-le m khng lm hng tip im.

Tui th c kh: c tnh bng s ln ng ngt, thng l vi trm ngn ln ng ngt khng in, v 1 trm ngn ln ng ngt c dng nh mc.


Thi gian tc ng: l khong thi gian k t lc dng in vt qu gi tr tc ng n lc phn ng c ht hon ton vo phn tnh, thng vo khong t 2 20ms.

Tn s tc ng: l s ln tc ng trong mt n v thi gian.V-R-le trung gian

R-le trung gian thc cht l mt r-le in t c kch thc nh, lm nhim v khuch i hoc chuyn mch tn hiu iu khin. Trong s iu khin, r-le trung gian nm v tr trung gian gia thit b iu khin cng sut nh v thit b iu khin c cng sut ln hn hoc gia cc thit b iu khin cng sut nh.

a) R-le trung gian

1) r-le trung gian

2) R-le trung gian

b) K hiu tip im r-le trung gian

1) Tip im thng m;

2) Tip im thng ng

Hnh -3.7. R-le trung gian.

R-le trung gian c cu to tng t r-le in t, nhng khng c c cu iu chnh lc ht, yu cu phi tc ng tt khi in p thay i trong phm vi ( 15% in p nh mc. Thi gian tc ng nhanh hn v tn s tc ng ln hn.

VI- R-le thi gian

R-le thi gian l mt r-le c chc nng to ra thi gian duy tr cn thit khi truyn tn hiu t mt thit b ny sang mt thit b khc.

Trong h thng iu khin, th r-le thi gian c s dng to thi gian tr cho c cu tc ng iu khin, bo v, V d trong h thng n xanh mt nt giao thng, rle thi gian duy tr n xanh sng 30 giy, n vng sng 5 giy, n sng 45 giy, hoc trong h thng bo v qu ti ca ng c in, khi ng c b qu ti, r-le thi gian duy tr vi giy trc khi tc ng bo v dng ng c, cho php loi b qu ti trong thi gian ngn m ng c c th chu c.

C nhiu nguyn tc to tr trong r-le thi gian, chng hn to tr bng c kh (c cu ng h quay tnh thi gian), to tr in t (s dng dng in cm ng to thi gian tr), to tr bng c cu thy lc (s dng piston thy lc to p sut phn khng khi tc ng), to tr bng mch in t.

Loi to tr bng c kh v thy lc c kch thc cng knh v gi thnh t nn ngy nay t c s dng. Hin nay loi r-le thi gian in t v in t c s dng rng ri.

a) R-le thi gian kiu in t

Gng t tnh

Vng ngn mch

Mch t

Cun dy

Gng t ng

L xo

L xo chng dnh gng t ng

Tip im tnh

b) Cu trc ca r-le thi gian in t

c) K hiu cun dy ca r-le thi gian

1) Tip im thng m, m chm 2) Tip im thng m, ng chm3) Tip im thng ng, m chm4) Tip im thng ng, ng chm

d) Cc loi k hiu tip im r-le thi gian

Hnh -3.8. R-le thi gian

VII-R-le dng in

R-le dng in c s dng bo v mch in khi dng in trong mch vt qu hay nh hn mt gi tr qui nh no .

Mch t

Cun dy

Tm ng hnh ch Z

L xo phn khng

Tip im thng m

Tip im thng ng

Hnh -3.9. R le dng in cc i

R-le dng in cc i c cu to nh hnh v, khi c dng in chy trong cun dy 2 th s to ra to ra mt t trng tc ng ln tm ng 3. Nu dng in vt qu gi tr t trc (nh l xo 4) th lc t s ln ht tm ng quay v thay i trng thi tip im (ng tip im 5, m tip im 6).

thay i dng in tc ng c th thay i cch ni hai cun dy A-a v B-b, chnh tinh th chnh lc cng l xo 4.

R-le dng in ny c s dng bo v dng in cc i, cun dy c ni tip vi mch cn bo v.

VIII-R-le in p

R-le in p c s dng bo v cc thit b in khi in p t vo thit b vt qu hoc gim qu mc qui nh. Cu to v hot ng ca r-le in p tng t nh r-le dng in. Ch khc l cun dy r-le dng in c tit din ln hn nhng t vng dy hn, cn cun dy r-le in p tit din nh hn v nhiu vng dy hn. Cun dy r-le in p mc song song vi thit b cn bo v.

IX-R-le nhit

9.1.Chc nng

R-le nhit ch yu c s dng bo v qu ti cho cc ng c in quay chiu.

9.2. Cu to

Cu to ca r-le nhit c minh ha hnh v 12a), cun dy in tr 1 gm mt vi vng dy mc ni tip vi mch cn bo v, thanh bi-metal 2 gm hai thanh kim loi mng c h s gin n nhit khc nhau c dn st vo nhau khi nhit tng th thanh s un cong, l xo 6 ko tip im ng ra khi thanh 2 cong ln, thanh truyn c cht quay 3, c cu hon nguyn 5.

1- Cun dy in tr

2- Tm thp bi-metal

3- Thanh truyn c cht quay4- Tip im tnh

5- C cu hon nguyn (reset)

6- L xo

7- Thanh lai tip im ng

e) c tnh A-s ca r-le nhit

1- ng c tnh r-le nhit

2- ng c tnh A-s ca thit b cn bo v

Hnh -3.10. R-le nhit a) Cu to r-le nhit b) R-le nhit sau khi tc ng

c) K hiu r-le nhit v tip im d) R-le nhit trong thc t

e) c tnh A-s ca r-le nhit

9.3.Nguyn l hot ng

Dng in chy qua cun dy in tr 1, khi dng in vt qu dng nh mc th cun dy in tr 1 nng vt qu mc qui nh lm cho thanh bi-metal 2 un cong ln, l xo 6 ko xung, tip im ng m ra (Hnh 8-12b) ngt mch iu khin a tn hiu n bo v thit b.

9.4.Cc thng s k thut

Cc thng s quan trng ca r-le nhit l:

Dng in bo v: l dng in m r-le nhit tc ng.

in p nh mc: l gi tr in p hot ng lu di ca thit b m r-le nhit bo v.

c tnh ampe giy ca r-le nhit (Hnh 8-12e): la chn ng r-le nhit c c ng c tnh A-s ca thit b v A-s ca r-le nhit gn st nhau, ng c tnh ca r-le nhit thp hn ng c tnh ca thit b mt t. Vi thit b cn bo v l ng c in th r-le nhit c chn sao cho hai ng c tnh ny ct nhau gi tr I/Im = 1.1 1.2.

X-Cu ch

10.1.Chc nng

Cu ch c s dng bo v ngn mch cho thit b in nh dy dn, my bin p, ng c in, cc mch in iu khin, mch in chiu sng,...

10.2.Cu to

Cu to ca cu ch gm cc b phn c bn l dy chy, rut cu ch, cu ch.

B phn c bn ca cu ch l dy chy. Dy chy c lm bng cc cht c nhit nng chy thp, thng l dy ch, km, hp kim ch thic, nhm, hoc ng. Dy chy c tit din trn hoc dt v c dp nh hnh.

Dy chy c t trong ng bo v v dp h quang pht sinh khi dy chy t. Ph thuc vo cp in p, dng in, mi trng lm vic, m dy chy c t trong cc loi v khc nhau, dy chy v v dy chy c gi l rut cu ch. Trong rut cu ch c th c mt vt liu dp h quang chng hn nh ct,

cu ch c lm bng gm, s, nha, ph thuc vo in p cch in yu cu, trn c b tr vt liu dn in v cc u ni dy.

10.3.Nguyn l hot ng

Khi dng in qua dy chy gi tr nh mc, dy ch khng chy, h thng hot ng bnh thng. Khi xy ra qu ti ln I >1.5 Im hoc ngn mch I >> Im, th dy chy t ngt mch in cn bo v ra khi li in. Dng cng ln th thi gian chy cng nhanh (xem c tnh A-s Hnh 8-13g)

10.4.Cc thng s k thut c bn

in p nh mc: l in p lm vic lu di ca mch in m cu ch bo v.

Dng in nh mc: l dng lm vic lu di ca cu ch.

Dng ngt: l dng m cu ch tc ng.

c tnh A-s ca cu ch (Hnh 8-13g)

a) Hnh dng mt s dy chyb) Hnh dng mt s rut cu ch

c) Cu ch xoy: rut v d) Cu ch hp: rut v

e) Cu ch ng: rut v f) Cu ch xoy: rut v

g) c tnh ampe-giy ca cu ch

Hnh -3.11. Cu ch

XI-Aptomat

11.1.Chc nng

Aptomat l kh c in c s dng t ng ct mch in, bo v qu ti, ngn mch, thp p, cho thit b in.

11.2.Cu to

Cu to ca aptomat c cc b phn chnh sau:

Tip im: aptomat thng c 2 n 3 loi tip im, tip im chnh, tip im ph v h quang. Vi cc aptomat nh th khng c tip im ph. Tip im thng c lm bng vt liu dn in tt nhng chu c nhit do h quang sinh ra, thng lm hp kim Ag-W hoc Cu-W. Khi ng mch th tip im h quang ng trc, tip theo l tip im ph, cui cng l tip im chnh. Khi ct mch th ngc li, tip im chnh m trc, tip theo l tip im ph, cui cng l tip im h quang. Nh vy h quang ch chy trn tip im h quang, do bo v c tip im chnh. Tip im ph c s dng trnh h quang chy lan sang lm hng tip im chnh.

Cu to aptomat

1-, 2-Cc tip im chnh

3- Tip im ph

4- Tip im h quang

5- Hp dp h quang

Mc bo v dng cc i

Cun ht (dng)

Mch t ng

L xo hi

Cn ch ng

Cn b ng

L xo m tip im

Mc bo v thp p

Cun p

Mch t ng

L xo hi

Cn ch ng

Cn b ng

L xo m tip im

c tnh A-s ca aptomat

on c tnh do phn t nhit bi-metal to ra

on c tnh do mch in t to ra

c tnh do cu ch to ra

Gi tr I1 tng ng dng bo v qu ti nh, I2 qu ti ln, I3 ngn mch.

Hnh -3.12. Aptomat

Hp dp h quang: thng s dng nhng tm thp chia hp thnh nhiu ngn ct h quang thnh nhiu on ngn dp tt.

11.3. Cc mc bo v

a) Mc bo v dng cc i (Hnh-3.12b): bo v thit b in khi b qu ti, c tnh A-s ca mc bo v phi nm di c tnh A-s ca thit b cn bo v. Cun ht in t 1 c mc ni tip vi thit b. Khi dng in vt qu gi tr cho php th tm thp ng 2 b ht, cn ch ng 4 c ko ln, l xo 6 ko cn b ng ra, tip im m ra ngt mch in qua thit b.

Mc bo v kiu r-le nhit: kt cu ny rt n gin nh r-le nhit bao gm phn t b) nung nng mc ni tip vi mch chnh, tm kim loi (bi-metal) gin n nh mc ngt tip im khi dng in qua thit b thit b ln. Nhc im ca loi ny l qun tnh nhit ln.

Mc bo v thp p (Hnh-3.12c): cun ht 1 mc song song vi mch in chnh, khi in p thp, lc ht ca cun ht gim yu hn lc l xo 3, mc 4 b ko ln, l xo 6 ko tip im aptomat ra.

11.4Cc thng s k thut c bn

in p nh mc: l gi tr din p lm vic di hn ca thit b in c aptomat ng ngt.

Dng in nh mc Im: l dng in lm vic lu di ca aptomat, thng dng nh mc ca aptomat bng 1.2 1.5 ln dng nh mc ca thit b c bo v.

Dng in tc ng It : l dng aptomat tc ng, tu thuc loi ph ti m tnh chn I tc ng khc nhau. Vi ng c in khng ng b 3 pha rotor lng sc th thng It = (1.2 1.5) It, vi It l dng nh mc ca thit b cn bo v.

c tnh A-s ca aptomat (Hnh 8-14d): aptomat bo v c thit b th c tnh A-s ca aptomat phi thp hn c tnh A-s ca thit b.



1Lp rp, kim tra cu to cc mch r leR le in p, r le dng inm r le thi gian, r le nhitTho v kim tra cu to bn trong v lp mch th hot ng

2Lp mch bo v ngn mch ca cu chNgun in, cu ch, dy in v bng nLp rp mch vi bong n. Th chp mch v kim tra cu ch

3Nu ng dng ca tng loi kh c inNhn bit tng kh c in v nu ng dng ca tng loi

D-CU HI NGHIN CU

-Trnh by ng dng ca cc loi kh c in nu trong bi

-Phn bit s khc nhau gia R le dng in v R le in p

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : THIT B IU KHIN V BO V

M bi : MD-M3-B3

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by ng dng ca cc loi kh c in Nu ng dng chnh cu tng loi kh c in hc trong bi

2Phn bit s khc nhau gia R le dng in v R le in p

Nu cc im khc nhau ni bt : cun dy, ng dng trong thc t v.v.

Bi 4 : CHNH LU DNG IN

M bi : MD-M3-B4

A-MC TIU THC HIN

-Trnh by nguyn l cu to c bn ca Diod bn dn-Nu s v ng dng ca cc mch chnh lu dng in xoay chiu thnh dng in mt chiu

-Bit lp rp cc mch chnh lu dng in p ng cho s dng di tu thy-Bit cch o v kim tra Diod bn dn

B-CC NI DUNG CHNH

-it bn dn

-Mch chnh lu cu mt pha

-Mch chnh lu na chu k

-Mch chnh lu hai na chu k

-Mch chnh lu

C-CC HOT NG HC TP


I-it bn dn

Tnh dn in ca cht bn dn.

Cht bn dn l cht trung gian gia cht dn in v cch in.

Cht bn dn thng gp trong k thut l cc nguyn t nh: Gecmani, silic, selentrc tin ta nghin cu c tnh dn in ca cht bn dn.

S lin kt ha hc ca hai nguyn t k nhau to thnh i in t gp chung gi l mi lin kt ng ha tr.

V d: Nguyn t Gecmani (Ge) l nguyn t tuc nhm th 4 trong h tun hon cc nguyn t ca Mendelep. Cc nguyn t thuc nhm ny c 4 nguyn t ha tr lp ngoi cng. Trong tinh th, mi nguyn t Ge c mi lin kt ng ha tr vi 4 nguyn t ln cn n to thnh 4 i in t gp chung. Nu khi nguyn t Ge hon ton nguyn cht th tt c cc in t ha tr ca nguyn t lin h vi nhau nn khng c in t t do v vy Ge khng dn in.

em t nng hay chiu chm phng x vo mng tinh th ny, cc in t c th b ph v mi lin kt, thot ra ngoi thnh in t t do. Gi l s dn n bng in t.

ch ni lin kt va b ph v, in t thot ra li mt l trng. L trng ny b mt in t mi lin kt khc nhy n lp l v lp tc xut hin mt l mi ch in t va ri khi. C th l trng di ng trong mng tinh th. Nh vy,l trng l ni thiu in t, tc l tha in tch dng. V th, khi xut hin l trng, lm tnh dn in ca khi tinh th tng ln. Trng hp ny gi l s dn in bng l trng.

tng mt l hay mt in t t do trong tinh th bn dn ngi ta pha thm tp cht.

Chng hn cho thm vo tinh th Ge mt lng nh nguyn t thuc nhm 5 nh Acsnic. Tinh th s tng mt in t t do ln rt nhiu. V acsnic c 5 in t lp ngoi cng. Trong mng tinh th mi nguyn t acsnic ch cn 4 in t gp chung vi 4 in t ca Ge xung quanh. in t th 5 d dng thnh in t t do v s lin kt yu t vi ht nhn.

Khc vi trc y, in t tch ra khng to thnh l do vy in t t do tng ln rt nhiu.

Nu cho vo tinh th Ge mt lng nh nguyn t thuc nhm 3 nh ini chng hn. Tinh th s tng mt l trng ln rt nhiu. V ini c 3 in t lp ngoi cng. Trong mng tinh th, mi nguyn t ini lin kt vi 4 nguyn t Ge bn cnh bng 3 in t nn thiu 1 in t tc l to thnh 1 l trng. V vy mt l trng tng ln rt nhiu so vi mt in t t do. Loi bn dn ny l bn dn l trng hay bn dn loi P.

Nguyn tc hot ng ca it bn dn.

it bn dn gm c hai lp bn dn khc nhau p v n tip xc vi nhau (H2-1)

ch tip xc p-n xy ra qu trnh vt l c bit gi l lp chuyn tip p-n. Do mt phn n ln nn chng khuych tn sang lp p. Ngc li l trng t p khuych tn sang n. kt qu n mt in t tch in dng. P nhn thm in t tch in m v ch chuyn tip hnh thnh mt in trng chuyn tip E chuyn tip in trng ny c tc dng ngn cn s dch chuyn ca in t t n sang p. V th lp chuyn tip cn gi l lp ngn.

in trng chuyn tip s khng tng na, khi lc in trng v lc khuych tn in tch cn bng nhau. Lc ny s in tch trung bnh chuyn qua lp ngn bng 0.

Ni it vi ngun in, cc dng vo u p, cc m vo u n. in p ngun sinh ra in trng ngoi E ngoi ngc chiu vi E chuyn tip. N kh in trng ny, tc l ph b lp ngn. Cc in t t n s d dng chuyn qua p. in tr it lc ny rt nh, dng in ln, ta ni it c phn cc thun (H1-10a)

Nu i chiu ngun in (H1-9b) th E ngoi cng chiu vi E chuyn tip lm lp ngn cng mnh v in t t n kh qua p v l trng t p kh qua n. Lc ny in tr it tng ln rt ln v dng in nh khng ng k. Ta bo it b phn cc ngc.

Nh vy, it ban n c c tnh dn in tt theo chiu p-n v gn nh khng dn in theo chiu ngc li.

S chuyn ng ca in t ti vng tip gip:

Do tnh cht bn dn cavt liu lm it m thit b ny ch cho php dng in xoay chiu chy qua theo mt chiu nht nh.

Nu ta c ngun in mt chiu ri th ta khng cn dng n it, u vo mch it l in p xoay chiu cn bin i, u ra l in p mt chiu a ti mch s dng. Do gii hn ca chng trnh ta khng th i su nghin cu m ch cng nhn tnh dn in mt chiu ca n ( tnh cht van mt chiu )

II-Mch chnh lu

Ngi ta dng it bn dn chnh lu dng xoay chiu thnh dng mt chiu, c th dng s ton sng hay na sng. Ngoi thc t loi c dng ph bin l s chnh lu kiu cu.

2.1.Mch chnh lu na chu k

S chnh lu pha na sng

Nguyn l lm vic

Na chu k dng ca dng inxoay chiu, dng in i t 1 qua qua R v 2. Na chu k m dng in b neon chn li.

2.2.Mch chnh lu hai na chu k- Nguyn l lm vic:

Na chu k dng ca dng xoay chiu, dng in i t 1 qua 1 qua R v 0.Na chu k m dng in i t 2 qua 2 qua R v 0.

Nh vy hai n 1 v 2 lun phin nhau lm vic tng na chu k.

2.3.Mch chnh lu cu mt pha

Nguyn l lm vic:

Na chu k dng ca dng xoay chiu (1) l dong (2) m mch thng theo vng (1) ( 1 ( (3) ( ti ( (4) ( 3 ( (2)

Na chu k m(1) m (2) dong. Mch thng theo vng (2) ( 2 ( (3) ( ti ( (4) ( 4 ( (1)

Nh vy, hai cp n thay nhau lm vic trong trng na chu k, b lc R-C san bng mp m ca dng in v in p trn ti.

HOT NG II : NGHE GII THIU V XEM TRNH DIN MU-S cu to ca cc ht bn dn, xem c tnh V-A ca Diod-Lp rp, o v kim tra cc mch chnh lu trong bi hcHOT NG III : RN LUYN K NNG


1u dy mch chnh lu na chu kNgun in xoay chiu, Diod bn dn, in tr ti, dy dn, bin p, ng h o dng in mt chiuLp rp ng mch, kim tra ng h xc nh dng in mt chiu chy trong ti

2u dy mch chnh lu hai na chu kNgun in xoay chiu, Diod bn dn, in tr ti, dy dn, bin p, ng h o dng in mt chiuLp rp ng mch, kim tra ng h xc nh dng in mt chiu chy trong ti

3u dy mch chnh lu cu 1 phaNgun in xoay chiu, Diod bn dn, in tr ti, dy dn, bin p, ng h o dng in mt chiuLp rp ng mch, kim tra ng h xc nh dng in mt chiu chy trong ti

D-CU HI NGHIN CU

-Trnh by cu to c bn ca Diod bn dn

-V s mch chnh lu cu 1 pha v nu ng dng

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : CHNH LU DNG INM bi : MD-M3-B4

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by cu to c bn v nu ng dng ca Diod bn dnDiod bn dn c cu to t cc lp ghp ca vt liu bn dn, c ng dng chnh trong chnh lu dng in xoay chiu thnh dng in mt chiu

2u mch chnh lu cu mt phaChun b thit b u, o xc nh v nu ng dng

Bi 5: AC QUY AXIT

M bi : MD-M3-B5A-MC TIU THC HIN

-Hiu c cu to v cc thng s ca c quy axit

-Trnh by v ng dng, cc bnh v cc ch hot ng ca c quy axit

-u ghp c c quy axit.

-Bit phng php an ton pha ch dung dc Axit sunfuric.

-Bit s dng v bo qun c quy axit

B- CC NI DUNG CHNH-Cu to ca c quy axit-Cc thng s nh mc ca c quy-Ch lm vic ca c quy-u ghp c quy-Cc phng php np in cho c quy-Bo qun c quy

-S dng c quy

C-CC HOT NG HC TP


Loi dng in dng trn tu thu l dng in xoay chiu v dng in mt chiu. V vy my pht in tu thu dng c hai loi my pht: my pht in xoay chiu v my pht in mt chiu.

i vi ngnh ng sng th hu ht cc tu u c trng ti nh v l c trng nn ti in nng trn tu sn phn nhiu l ti nh sng, ng c man v mt s ng c xoay chiu cng sut nh hoc ph ti nh khc.v.v.V vy trang b my pht trn tu a phn l my pht in xoay chiu cng sut nh v my pht in mt chiu dng cho ti nh sng, np c quy. c quy gp phn rt quan trng trong ngun in nng tu thu.

I-Cu to ca c quy axit

1.1.V bnh

V bnh c c bng nha tng hp Ebonit, y l loi nha chng c n mn ca dung dch axit, c bn c hc cao.

y v bnh c sng cc tm bn cc vi mc ch hn ch hin tng chp mch bn trong c quy.

Mi ngn ca c quy c mt np y bng nha Ebonit v c gn vi v, mi np u c l dung dch, trn l c nt bng nha v c ren lp cht vo np bnh, trn mi nt u c l thng hi, cc ngn ca c quy c u ni tip vi nhau bng tm ch.

1.2.Chm cc

a.Tm bn cc

Tm bn cc l mt li bng ch c pha (6 - 7)% ng ti moan tng bn c hc cho li , ti cc mt li nht y cht tc dng l xit ch ( Pb3O4 ) v PbO nho vi axit sunfuric ( H2SO4 ) da vo phng php in phn c bit m sau bn cc dng cht tc dng tr thnh PbO2 c mu nu.

Cn bn cc m cht tc dng tr thnh ch xp nguyn cht c mu xm sng.

b.Chm cc

tng dung lng cho c quy th mi c quy gm nhiu bn cc dng v nhiu bn cc m, cc bn cc dng hp thnh chm cc dng.

Cc bn cc m hp thnh chm cc m.Vy chm cc bao gm nhiu tm cc ghp li song song vi nhau.

1.3.Tm cch in

a.Cu to (H-5.1)

Tm cch in lm bng g mng hoc nha mng c nhiu l, trong nhiu trng hp tm cch in cn c lm bng thu tinh si.

Yu cu ca tm cch in l phi mng v c nhiu l cho dung dch in phn thm qua.

Tm cch in c t gia chm cc m v chm cc dng nhng chm cc m v chm cc dng c ghp sao cho: Mt chm cc dng bao gi cng nm gia 2 chm cc m v nh vy chm cc m bao gi cng nhiu hn chm cc dng mt chm cc trong t c quy.

1.4.Dung dch

Dung dch in phn l dung dch ca axit sunfuric ( H2SO4 ), dng H2SO4 nguyn cht pha vi nc ct theo t l (24 33)%, ty theo iu kin lm vic khc nhau m nng dung dch H2SO4 trong c quy khc nhau. Nu nng cao th kch thc, trng lng c quy nh, dung dch kh b ng c nhng hin tng sunft ho li xy ra nhanh, cc tm ngn d b ph hu nht l cc tm ngn bng g do tui th ca c quy gim.

c quy t trn tu thu c nng dung dch khong 1,2g/cm n 1,28 g/cm. V ma h nn pha dung dch c nng thp hn so vi ma ng.

II-Cc thng s nh mc ca c quy

2.1.in p nh mc (V)

in p nh mc ca 01 ngn n khi np no l 2,4V, nhng thc t ghi trn bnh nh sau : mt bnh c 06 ngn th in p ca bnh l 12V. V vy xc nh bnh cn dung lng hay khng ta phi cho bnh phng vi dng nh mc mi bit, cch tt nht l dng T trng k hoc Ph k o nng dung dch l bit.

2.2.Dung lng nh mc (Ah)Dung lng nh mc ca bnh c gi l Q (Ah), l kh nng phonngs in ca bnh vi dng in nh mc trong thi gian 10 gi

2.3.Dng in nh mc (A)

T nh ngha v Dung lng nh mc ca bnh c quy tta c th tnh c dng in nh mc ca bnh l : Im = Qm/10 (5.1)

III-Ch lm vic ca c quy

3.1.Ch np

a.S H-5.2R: Bin tr dng tng gim dng np

A:ng h ampe o dng np

MF: my pht in mt chiu

b.Qu trnh np v phng trnh phn ng

np in cho c quy ta ni c quy vi cc dng ca ngun np tng ng v cc m ca c quy vi cc m ca ngun np.

Khi np th cht tc dng trn bn cc c quy s hon nguyn nh c, nc mt i, H2SO4 c tr li nn nng dung dch tng do mun dng in np khng i ( np bng dng khng i ) th ta phi tng dn in p np c quy cn bng vi sc in ng c quy. Khi in p ca mt ngn n t 2,4V th cht tc dng trong cc bn hu nh c hon nguyn, in nng lc ny a vo c quy ch in phn nc thnh Hyr v xy, chng thot ra ngoi lm cho dung dch si bt ( ta ni c quy si ) in p tng vt ln 2,7V, n lc ny c th ngng np nhng chc chn ta c th np thm 1 - 2 gi na, khi thy in p trn cc v nng in phn khng tng na th ta c th ngng np.

Tm li, du hiu nhn bit mt c quy c np no hon ton l:

c quy si mnh,

in p trn cc ca mt ngn n t 2,7V v gi khng i,

Sau khi ngng np mt thi gian nng in phn cn bng gia cc l bn trong bn cc v ngoi, in p c quy tt xung gi tr n nh 2,1 - 2,2V.

Phng trnh np:

2PbSO + 2HO = PbO + 2HSO + Pb (5.2 )

3.2.Ch phng ca c quy

a.S H-5.3

R: Bin tr dng tng gim dng ti,

A:ng h ampe o dng ti,

C:ng c in mt chiu.

b.Qu trnh phng v phng trnh phn ng

Qu trnh phng in l qu trnh ng ti vo c quy, dung lng ca c quy ph thuc vo rt nhiu gi tr ca dng in phng, c quy phng vi dng in ln th dung lng ca n cng mau ht v dng in phng cng ln th nng dung dch in phn cc l bn trong cc bn gim rt nhanh do in p trn 2 cc c quy gim nhanh.

Khi phng in cht tc dng bn cc m v bn cc dng bin thnh Sunft ch PbSO v ng thi nc c to thnh theo phng trnh sau:

PbO + 2HSO + Pb = 2PbSO + 2HO (5.3 )

Sau thi gian phng th dung dch long ra, Sunft ch l cht khng dn in nn khi phng in th in tr trong ca c quy tng ln v cng vi nng gim nn in p trn cc c quy gim i. Dng in phng cng ln th in p cng gim nhanh. Nu c quy phng vi dng in ln th cht tc dng trn cc bn bin i khng u v cc b vnh, tui th gim. c quy phng in ti khi trn cc cn 1,7 - 1,8V phi ngng phng, nu c tip tc phng Sunft ho to nn trn bn cc qu nhiu c th lm cho c quy b hng v khng dng c.

Tm l: du hiu bit mt c quy ch phng ht v cn phi np li l: in p mt ngn n cn 1,7 1,8V, trng lng ring ca dung dch tt xung cn 1,05 1,1g/cm.

H-5.4

IV-u ghp c quy4.1.u ni tip c quy

a.S (H-5.5)

b.iu kin

Q1 = Q2 = Q3 = . . . . . . . . =Qn (5.3)

c.Kt quUT = U1 + U2 + U3 + . . . . . + Un (5.4)

Q = Q1 = Q2 = Q3 = . . . . . . . . =Qn (5.5)

*u ni tip nhiu bnh c quy ta c t c quy tng v in p cn dung lng khng tng.

Trong trng hp ti c in p cao nhng cng sut nh ta dng t c quy u ni tip.

4.2.u song song

a.S (H-5.6)

b.iu kin

U1 = U2 = U3 = = Un (5.6)

c.Kt qu

Q = Q1 + Q2 + Q3 + +Qn (5.7)

U = U1 = U2 = U3 = = Un (5.8)

*u song nhiu bnh c quy ta c t c quy tng v dung lng cng in p khng tng

Trong trng hp ti c in p thp nhng cng sut ln th ta dng t c quy u song song

4.3.u hn hp

a.S (H-5.7)

Ta v d t c quy u hn hp gm 04 bnh

Nh sau:

+.iu kin

U1 + U3 = U2 + U4 (5.9)

Q1 = Q3 ; Q2 = Q4 (5.10)

+Kt qu

U = U1 + U3 = U2 + U4 (5.11)

Q = Q1 + Q2 = Q3 + Q4 (5.12)

*u hn hp nhiu c quy ta c t c quy tng c v in p v dung lng.

Trong trng hp ti c in p cao v cng sut ln th dng t c quy u hn hp.

V-Cc phng php np in cho c quy

Vi c quy cn mi em ra s dng ln u th trc khi em s dng phi rt y dung dch in phn c nng ph hp. Dung dch phi cao hn bn cc 15 20mm. Nhit dung dch khong 25 - 300C. Sau khi dung dch t 4 12 gi th c th tin hnh np.

Khi np in cho c quy, ni c quy vi b np thch hp. Cc dng c quy ni vi cc dng ngun v cc m c quy ni vi cc m ngun. C hai phng php nap c quy.

5.1.Phng php np vi dng khng i: trong qu trnh np, dng np c gi khng i bng cch tng in p np theo s tng dn sc in ng trong c quy, khi np no th in p n nh.

5.2.Phng php np vi in p khng i: trong qu trnh np th in p np khng thay i, dng np gim dn, khi np no th dng np bng 0.

Du hiu ca c quy np no l in p khng i trn cc c quy v dung dch c nng n nh trong 3 gi lin.

Vi c quy ang s dng th c quy c gn vi thit b np t ng do qu trnh phng np xy ra hon ton t ng.

i vi c quy axit khi tin hnh pha dung dch in phn ta phi t t axit sunphuritc (H2SO4) vo nc ng thi cm que thy tinh khy u dung dch, phi rt t t st mt nc. Tuyt i khng nc vo axt, v khi pha dung dch pht nhit nhiu nn nu rt nc vo axit, dung dch s si v bn ln rt nguy him. Khi tip xc vi axit phi eo knh, mang gng tay cao su, mc o qun chng axit.

Thng xuyn kim tra v sit cht cc u cp bt vo c quy trnh gy ra tia la.

Khng c ht thuc l v mang cc vt liu pht la vo phnh c quy.

i vi c quy kim th qu trnh pha ch dung dch in phn rt nguy him. Cht kim ri vo da s bng nng. Phi mang knh khi p vn Kali, dng kp gp mnh kim.

a) c tnh phng php dng np khng ic tnh phng php in p np khng i

H-5.8 c tnh np c quy theo cc phng php khc nhau

VI-S dng c quy

6.1.Np in cho c quy

Np in cho c quy mi: mun ko di tui th cho c quy th khi np in ln u tin ta phi dung dch vo bnh ngm t 4 - 6 gi dung dch thm u vo tm bn cc. Khi dung dch ngui ( nhit < 30C ) ta tin hnh np, dng in np bng 1/14 - 1/20Q.

+ Trong sut thi gian np khng c ngng khi c quy cha no in,

+ Nu nhit c quy ln hn 45C th phi gim dng np i mt na,

+ Gn cui qu trnh np th c mt gi ta li kim tra t trng v in p ca c quy mt ln: t trng 1,26 - 1,28g/cmv n nh, in p 2,75 - 2,8V v n nh. Trong 3 gi lin tc m t trng v in p khng thay i th ngng np tc l c quy ca ta hon ton no.

- Np in b sung cho c quy:

+ dung dch sao cho trong mi ngn n dung dch phi ngp trn bn cc t 10 - 15mm.

+ Cc nt bnh phi thng hi tt.

+ Cc im ni dy ca mch np phi bt cht.

Sau tin hnh np:

+ Khi in p ngun np t gi tr nh mc th ta ng cu dao np.

+ Kim tra Ampe k sao cho dng in np bng 7 - 10%Q, trong qu trnh np nu ampek bo dng np gim dn theo thi gian th chng t c quy cn tt.

+ Khi np nhit dung dch khng c ln hn 45C.

+ Khi thy dung dch si bt trong cc ngn ng u v nhiu. ng thi ampe k bo gi tr thp v n nh l c. m bo chc chn th ta kim tra t trng v in p ca bnh: in p mt ngn n khi cn ang np khong 2,75V v u cc ngn , t trng bng 1,26 1,28g/cm ( ng vi 26 - 28B ) v n nh th chc chn c quy no in, ta tin hnh ngt cu dao np trc khi tho u dy tr c quy.

6.2.Phng in

Nu c quy phng in trong thi gian di, dng in phng khng qu 1/10Q, thi gian phng ti a khi in p mt ngn n cn 1,75V. Phng vi dng in ln nh khi khi ng ng c Diesel th mt ln phng t 3 - 5 giy, s ln phng lin tc khng qu 3 ln, gia 3 ln phng lin tip th phi c thi gian ngh khong 10 - 15 giy c quy h thp nhit v phc hi dung lng.VII-Bo qun c quy

7.1.Bo qun hng ngy

Hng ngy ta phi thng xuyn lau chi sch du, m, nc mn bm vo c quy, che y cho c quy trnh b tia nc, tia la, khng c quy ni c nhit cao .

Kim tra dung dch trong c quy, nu thiu th ta thm, dung dch bao gi cng ngp trn tm bn cc 10 15mm.

Kim tra in p ca c quy, nu cn thp hoc khng th ta phi np b sung.

Khi np cho c quy phi vn lng nt bnh.

Khi phng in vi dng ln nh khi khi ng ng c Diesel th phi vn nt bnh ra trnh hin tng n bnh khi phng vi dng ln.

7.2.Bo qun c quy d tr

i vi c quy d tr th c 2 loi: nu l c quy mi nhng cha dung dch ta phi trong kho sch, thong mt, khng xp chng ln nhau. Nu l c quy mi nhng dung dch th phi lu tr trong kho thong c qut thng gi, nh k np b sung cho c quy.

7.3.Quy trnh np c quy

a.Pha dung dch

+Chun b

Nc ct v axit Sunfurc (HSO) nguyn cht, hai bnh ny c nh du,

Dng c pha ch dung dch phi chu c axit: go mc dung dch, a khuy, lu hoc chu

a im pha ch: pha ni thong mt v t ngi qua li,

Chun b dung dch kim ra axit bn to,

Qun o v bo h lao ng.

+Cch pha v kim tra t trng dung dch

-Ngi pha dung dch phi mc qun

o bo h, eo khu trang, knh bo h

- nc ct vo lu ( hoc chu ) sau

t t axit vo nc ( tuyt i khng

c nc vo axit ), sau ly a khuy

u axit trong nc ct.

-Khi nhit dung dch h thp bng nhit mi trng ta dng ph k hoc t trng k kim tra t trng dung dch ( thng pha vi t trng t 1,22 - 1,24g/cm, ng vi 26 - 28B ) t trng o c cao hoc thp hn so vi quy nh, phi dng nc ct hoc HSOnguyn cht iu chnh: nu t trng cao hn quy nh th phi pha thm nc ct, nu t trng thp hn quy nh th phi pha thm axit.

-Trong khi pha nu chng may b axit bn vo ngi th ta phi ly vi nhng vo dung dch kim lau sch ri ly nc trong ra sch.

b.Np in cho c quy mi

+Chun b

Mun ko di tui th cho c quy th khi np in cho c quy mi ta phi tun th theo cc bc sau:

dung dch vo bnh ngm t 4 - 6 gi dung dch thm u vo tm bn cc,

Chun b ngun np c in p bng vi in p nh mc ca c quy,

Xc nh cc tnh ca ngun np v cc tnh ca bnh c quy sau chun b dy v thit b u np.

+Np in

Khi nhit dung dch < 30C ta tin hnh np, dng in np bng 1/14 - 1/20Q, cho n khi in p mt ngn n t gi tr nh mc th tin hnh phng, phng cho n khi in p mt ngn n cn 1,75V th ngng phng v np in li cho c quy. Lm lp i lp li nh vy gi l np - phng tun hon, thi gian np -phng tun hon khong 60 - 72 gi th em c quy np s dng.

Trong sut thi gian np khng c ngng khi c quy cha no in.

Nu nhit c quy ln hn 45C th phi gim dng np i mt na.

Gn cui qu trnh np th c mt gi ta li kim tra t trng v in p ca c quy mt ln: t trng 1,26 - 1,28g/cmv n nh, in p 2,75 - 2,8V v n nh. Trong 3 gi lin tc m t trng v in p khng thay i th ngng np tc l c quy ca ta hon ton no.

c.Np in b sung cho c quy

+Khi no cn a c quy vo np in b sung?

Bt k lc no ta cng c th np in b sung cho c quy, sau khi ta phng th dung lng ca c quy nh hn nh mc ( Q < Q ).

tin hnh np b sung ta phi kim tra :

Dung dch trong cc ngn n phi ngp trn tm bn cc t 10 15mm ( cng vic ny c th phi kim tra thng xuyn trong mi ln np nu ngy no cng np b sung ),

Cc nt phi thng hi tt,

Cc im ni dy ca mch phi bt cht v tip xc tt,

Ngun np phi ph hp.

+Cch np

Khi in p ngun np t gi tr nh mc th ta ng cu dao np,

Kim tra Ampek sao cho dng in np bng 7 10%Q, trong qu trnh np nu ampek bo dng np gim dn theo thi gian th chng t c quy cn tt,

Khi np nhit dung dch khng c ln hn 45C,

Khi thy dung dch si bt trong cc ngn ng u v nhiu, ng thi ampek bo gi tr thp v n nh l c. m bo chc chn th ta kim tra t trng v in p ca bnh: in p mt ngn n khi cn ang np khong 2,75V v u cc ngn, t trng bng 1,26 1,28g/cm ( ng vi 26 - 28B ) v n nh th chc chn c quy no in ta tin hnh ngt cu dao np trc khi tho u dy tr c quy.

d.Np kh Sunft ho

+Chun b

Bnh Sunft ho: hin tng m khi np t trng tng chm v khng t nh mc, nhit dung dch tng nhanh ti qu mc quy nh, dung dch si bt sm ( hay cn gi l c quy no sm ).

Khi pht hin bnh c quy b bnh Sunft th ta phng in c quy cho n khi in p mt ngn n cn 1,75V th ngng phng. dung dch ra v cho nc sch vo bnh sau xc ra nhiu ln cho sch, nc ct vo thay dung dch.

+Np in

u c quy vi ngun np v np vi dng np bng 1/14 1/20Qcho n khi c quy no in,

Cho c quy phng vi dng phng bng I= 1/10Q cho n khi in p mi ngn n cn 1,75V th ngng phng,

Xc ra bnh ln th 2 : dung dch c nng 5B, tip tc np v phng nhiu ln (tu theo bnh b Sunft ho nng hay nh ). Trong khi np th c 1 gi kim tra t trng cc ngn n mt ln, nu t trng cc ngn tng dn l tt, khi c quy no in th nng c th khong 14 - 16B,

dung dch trong bnh ra, dung dch c nng 26 - 28B vo bnh tin hnh np nh np in b sung cho n khi c quy no in l xong.

7.4.Cc bnh thng gp c quy

a.Bnh Sunft ho

+Hin tng

Nhn qua l dung dch thy nhiu m trng to ph trn cc bn cc, vu cc v cc tm ngn,

Bnh Sunft ho hin tng m khi np t trng tng chm v khng t nh mc, nhit dung dch tng nhanh ti qu mc quy nh, dung dch si bt sm ( hay cn gi l c quy no sm ),

Khi np: giai on u in p tng rt nhanh, sau th in p tng chm v khng tng ti nh mc, khi phng th mau ht.

+Nguyn nhn

Phng in trong thi gian di khng np b sung,

Thng xuyn np cha no em s dng,

Dung dch khng ngp trn tm bn cc.

+Khc phc

Thng xuyn np b sung cho c quy,

Mi ln np phi np no mi em s dng,

Dung dch phi lun lun ngp trn tm bn cc 10 - 15mm,

T trng dung dch vo bnh t 1,22 1,24g/cm( 26 - 28B ),

Khi b Sunft ho ta phi thay dung dch v xc sch c quy.

b.bnh chp mch trong

+Hin tng

Khi np in th in p ca bnh tng chm v khng t nh mc, dng np rt ln v dung dch nhanh si,

Khi phng th in p ca bnh gim nhanh v c th bng 0,

Sau khi thi np th in p bnh cng c th bng 0 lun.

+Nguyn nhn

Dung dch nhiu tp cht hoc c quy s dng lu nn cht tc dng ri xung y bnh nhiu,

Tm ngn b hng hoc cc bn cc b cong vnh.

+Khc phc

Xc ra bnh, dung dch mi v em np li,

Thay tm ngn.

c.Bnh t phng

+Hin tng

y l bnh m khi ta khng s dng c quy ( khng phng in ) m c quy vn mt in mc d trc ta np no.

+Nguyn nhn

B ni tt cc u cc ca bnh hoc ca tng ngn do bi bn hoc dung dch trn trn np,

Do khng ng u v nng gia cc lp dung dch trong bnh ( c quy bo qun lu, dung dch b lng xung hoc ta thm nc ct vo dung dch nhng khng np b sung ). Lc ny in th phn di cao hn in th phn trn v lm xut hin dng in chy trong bnh, t c quy mt dn in.

+Khc phc

Mt bnh phi lun lun kh ro v sch se,

c quy khng s dng phi thng xuyn np b sung trn u dung dch trn v di.

Khi chm thm nc ct cho c quy th phi np in cho c quy.

HOT NG II : NGHE GII THIU V XEM TRNH DIN MU

-Cu to ca c quy axit

-Pha ch dung dch axit ng nng v m bo an ton

-u ghp c quy theo ng s v nu iu kin, kt qu



1Nu cu to ca c quy axitBnh c quy cNhn bit cc thnh phn cu to

2u ni cho c quy hai ch : np v phngBnh c quy, dy in, ngun in xoay chiu, bong n, b scu np in cho c quy, xem xt v a ra cc nhn xt.u phng in cho c quy

3u ghp cc c quy thnh t : song song, ni tip v hn hp04 bnh c quy, dy dnu ng s ca tng mch, a ra nhn xt, nu iu kin v kt qu

D-CU HI NGHIN CU

-Trnh by cu to v nguyn l hot ng ca c quy axit-Trnh by cc ch lm vic v ng dng ca c quy axit-Nu diu kin v kt qu ca tng phng php u nghp c quy axit.

-Trnh by nguyn nhn, hin tng v bin php khc phc cc bnh thng gp c quy axit.

-Trnh by phn php bo qun v s dng c quy axit

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : C QUY AXIT

M bi : MD-M3-B5

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Nu cu to v ng dng ca c quy axitNu cu to v cc ng dng ca c quy axit di tu thy

2Nu cc thng s v bin php bo qun s dng c quy di tu thyNu bt thong s Ah, bo qun v s dng an ton di tu

3C my phng php u ghp c quy, hy v hnh v trnh byNu bt ba phng php u ghp, nu ng dng ca tng loi t c quy di tu thy

Bi 6 : MY PHT IN

M bi : MD-M3-B6

A-MC TIU THC HIN

-Hiu c cu to, nguyn l hot ng ca my pht in mt chiu di tu thy-Hiu c cu to, nguyn l hot ng ca my pht in xoay chiu di tu thy

-Nm c cc thong s ca my pht in mt chiu v my pht din xoay chiu

-Nhn bit c chc nng v ng dng ca cc my pht in trang b trn tu thy

-Bit u ni cc my pht khi cn s dng, tho rp v v sinh cc my pht inB- CC NI DUNG CHNH-My pht in mt chiu

+Cu to v cc thng s

+Nguyn l hot ng v ng dng

-My pht in xoay chiu ba pha

+Cu to v cc thng s

+Nguyn l hot ng v ng dng

+Cc phng php u dy v ng dng thc t

C-CC HOT NG HC TP


I-My pht in mt chiu1.1.Cu to

a.Phn cm ( Stato )

S 1 : Cc t

S 2 : Dy quni vi my pht in mt chiu Stato l phn cm ( Ngc li i vi my pht in xoay chiu ). Cu to bao gm v c bng thp hoc gang, cc t c ghp bng cc l thp k thut in dng mng sau bt cht vo v my, cun dy c lm bng ng bc cch in qun trn cc t.

b.Rto ( phn ng )

Rto cng bao gm li thp t v cun dy. Li thp c hnh tr v c lm bng cc l thp k thut in, cc l thp ny c dy 0,5mm, c ph sn cch in v p cht li, cc l thp c dp c l thng gi v x rnh t dy qun phn ng.

Dy qun phn ng c nhiu cun dy qun lch pha nhau v c u ni tip vi nhau thng qua cc phin gp trn c gp in ( y khng trnh by cch qun dy).+Vnh i chiu ( c gp in )

C gp gm cc phin gp lm bng ng v c p cch in c dng hnh tr sau c gn cht trn trc Rto.

+Chi in ( chi than )

Chi than c lm bng than ch Grapht, cc chi than c t cht ln c gp nh l xo v gi chi than, sau c chi than v gi chi c gn trn np my. (H-6.3)

1.2.Nguyn l hot ng ca my pht in mt chiu

a.Nguyn l hot

My pht in mt chiu hot ng theo nguyn l cm ng in t, v nguyn l c bn th n cng ging nh my pht in xoay chiu nhng do cch ly tn hiu in ra ngoi m in p ly ra l in p mt chiu nh thit b chnh lu c kh l chi than v c gp.

a ngun in mt chiu vo cun dy kch t, dng in ny sinh ra t trng chnh trong mch, khi ng c s cp quay phn ng lc ny cc thanh dn ca dy qun phn ng ct t trng chnh lm cm ng cc sc in ng. Chiu ca sc in ng xc nh theo quy tc bn tay phi. Nh hnh ti v tr s 1 ta thy t trng hng t cc N n cc S, chiu quay ca phn ng ngc vi chiu kim ng h, thanh dn pha trn sc in ng c chiu t a n b. thanh dn pha di sc in ng c chiu t d n c, sc in ng ca phn t bng hai ln sc in ng thanh dn. Nu ni hai chi in A v B vi ti, trn ti s c dng in, in p ca my pht in c cc dng chi A v m chi B. Hnh H-6.4

Khi phn ng quay c na vng ta thy ti hnh v tr s 2, lc ny v tr ca phn t thay i, thanh ab cc S, thanh dc cc N, sc in ng trong thanh dn i chiu nhng nh c chi in ng yn, chi A vn ni vi phin gp pha trn, chi B ni vi phin gp pha di nn chiu dng in mch ngoi khng i. Ta c my pht in mt chiu vi cc dng chi A v cc m chi B.b.Cc i lng c trng

+Sc in ng

Khi quay Rto, cc thanh dn ca dy qun phn ng ct t trng, trong mi thanh dn cm ng sc in ng l:

e = B.l.v ( 6.1 )

Trong :

B : Cng cm ng t trung bnh di cc t.

v : Tc di ca thanh dn.

l : Chiu di tc dng ca thanh dn.

Dy qun phn ng gm nhiu phn t ni tip nhau to thnh mt vng kn. Cc chi in chia dy qun thnh nhiu nhnh song song, sc in ng phn ng bng tng cc sc in ng cc thanh dn trong mt nhnh.

Nu gi s thanh dn ca dy qun l N, s nhnh song song l 2a ( trong a l s i nhnh ) vy s thanh dn ca mt nhnh l nn ta c sc in ng phn ng l:

E = .e = . B.l.v ( 6.2 )

Trong :

Tc di v =

T thng ( di mi cc l ( = B.

Thay vo cng thc E ta c : E = .n. (t k =

Cui cng ta c: E = k.n. ( (6.3 )

+in p Gi U l in p 2 tr ni dy ca my pht, I l dng ti, R l in tr ca cun dy phn ng, R l in tr tip xc ca chi than vi c gp, (U l tn hao in p trn chi than.

Ta c:

U = E I . R - (U ( 6.4 )

Do R v (U l 2 gi tr nh nn c th b qua

U = E I . R ( 6.5 )

-Cng sut in t

P = E . I (6.6 )

Thay E vo ta c:

P = .n. (. I ( 6.7 )

-M men in t

M = ( 6.8 )

Trong l tn s gc quay ca Rto c tng theo tc quay n ( v/ph ) v biu thc l:

= ( 6.9 )

Thay vo ta c:

M= . I .( ( 6.10 )

t k = v y gi l h s mmen

= k. I .( ( 6.11 )

M men in t t l vi I v ( nn mun thay i m men in t ta phi thay i I hoc thay i ( hoc thay i c hai.

II-My pht in xoay chiu ba phaM u

Hin nay trn tu c rt nhiu phng tin hin i, thit b t ng, Raa. Do tnh u vit ca ngun in xoay chiu: n c th thay i tr s in p mt cch d dng, truyn ti in nng i xa m khng tn hao ln, ngun in xoay chiu bin i thnh ngun in mt chiu thng qua b chnh lu m gi thnh khng cao, my pht in xoay chiu d ch to, d s dng v vn hnh. My in xoay chiu hot ng c tin cy cao v cng sut di ln. ng c in xoay chiu rt d ch to v hot ng tin cy. Nn hin nay a s cc tu ng mi u s dng ngun in nng xoay chiu.

Mc d vy cng c rt nhiu nhc im: chng hn nh khi lng ln nn gi thnh u t ban u ln, n chim din tch trong hm my, cc h thng km theo n rt kh hiu nguyn l v c bit l tnh an ton i vi con ngi khi vn hnh h thng in nng xoay chiu.

Mt iu t ra l cp nht c vi s pht trin th my trng hay th my tu sng phi kp thi nm bt, b sung kin thc v ngun in nng xoay chiu cng s an ton khi lm vic vi ngun in nguy him ny.

2.1.Cu to v nguyn l hot ng

a.Cu to (H-6.6) +Stato (phn ng)

- V my

Thng c c bng gang, trn b mt c c g gh to ra cc cnh tn nhit gip cho ng c thot nhit v lm mt tt.

- Li thp

C hnh tr v c ghp bng cc l thp k thut in, cc l thp ny ghp cht vi nhau to thnh hnh tr, trn b mt li thp c phay cc rnh t cun dy. Li thp c bt cht vi v my.

- Dy qun

Dy qun c lm bng ng hoc nhm ( thng lm bng ng ) v dy bc lp sn cch in, dy c t di rnh ca li t v c u ni tip vi nhau to thnh 3 cun mi cun t lch nhau 120 in, ba cun dy ny gi l cun dy phn ng ca my pht in xoay chiu ba pha. Chng c u Y hoc u ( tu mc ch s dng.

- Chn my

Chn my c c bng gang hoc bng thp v bt cht vi v my, chn my c l bt bulng c nh my pht vo tu hoc v tr c nh.

b.R to (phn cm)R to my pht in xoay chiu ba pha c 2 loi: Rto cc n v Rto cc hin (cc li ).

- Rto cc n (H-6.7)

Rto cc n c ghp bng cc l thp

k thut in to thnh hnh tr, trn b mt c phay cc rnh t cun dy. Nu nhn bng mt ta khng th pht hin c Rto c my cc.

- Rto cc hin (H-6.8)

Rto cc hin cng c dng hnh tr, c ghp t cc l thp k thut in, gn cht vi trc ca my pht, nu nhn trc quan ta bit c Rto ca ta c my cp cc.

2.2.Nguyn l hot ng ca my pht in xoay chiu ba pha

a.S

b.Nguyn l hot ng

(Xt my pht 1 pha nh hnh v H-6.9)

My pht in xoay chiu 3 pha hot ng theo nguyn l cm ng in t.

nhn c in p ba pha trn ba cun dy Stato ta t ba cun dy lch nhau 120 in v u Y hoc u (.

Dng in mt chiu sinh ra t trng khng i c to ra bng cch a vo cun dy kch t mt in p mt chiu qua 2 vnh trt.

Gn trc Rto ca my pht vo trc ca ng c lai v quay vi tc n, ta c mt t trng quay trn c t thng chnh ( khp kn qua Rto, cc t v li thp Stato. T thng ny ct cc cun dy Stato lm xut hin trong ba cun dy 3 sc in ng cm ng eA, eB v eC .

Tn s bin thin ca cc sc in ng ny ph thuc vo tc quay ca Rto.

Ta c cng thc:

f = (6.12)

Trong :

f:Tn s, n v tnh l Hc (HZ).

n: Tc quay ca Rto (v/ph).

p: S cp cc ca Rto.

Nu ba pha ca my pht in c ni vi ba ti i xng th trong my xut hin dng in ba pha i xng.

2.3.Cc thng s nh mc ca my pht in xoay chiu ba pha

Thng s nh mc l thng s m my pht hot ng c gi tr kinh t nht.

Thng s k thut ca my pht in xoay chiu ba pha ch yu l cc thng s nh mc m my pht hot ng trong ch khng ti hoc ch ti nh mc, sau y l cc thng s c bn ca my pht:

a.in p nh mc ( Um)

in p nh mc ca my pht l gi tr in p m khi ta a dng kch t c gi tr nh mc, quay Rto ca my pht vi gi tr nh mc th my pht pht ra mt in p nht nh v gi tr in p ny gi l cp in p nh mc.

My pht xoay chiu ba pha thng c cp in p nh mc l:220V, 380V, 400V . v. v Nu nh trn bin my m l Y/YY - 380/220V th c ngha l nu u sao (Y) my pht 3 pha c cp in p l 380V, nu u sao kp (YY) my pht 3 pha c cp in p l 220V.

b.Dng kch t nh mc ( Iktm )

Dng in kch t nh mc l dng in mt chiu a vo cun dy kch t ca my pht my pht pht ra in p nh mc ng vi tc quay nh mc ca ng c s cp.

Gi tr dng ny tu thuc vo cng sut ca my pht: c th l 10A, 15A, 20A .v.v

c.H s Cos( nh mc

y l thng s c trng cho tnh k thut v tnh kinh t ca my pht, nu ta bit c h s ny v dng ti tng ng vi cp h s Cos( nh mc s gim c tn tht in nng do tiu tn cng sut v cng ca my pht, trnh c st p ln cho my pht.

Thng h s ny c cc gi tr l: 0.75, 0.8, 0.85, 0.9, 0.95.v.vNu h s ny cng cao th my pht l loi my pht cng tt.

d.Cng sut nh mc ca my pht

Cng sut nh mc ca my pht ni nn kh nng chu ti ca n: nu dng ti thp hn nh mc s d tha cng sut dn n khng kinh t, nu dng ng ti nh mc s m bo tnh kinh t khi khai thc, nu dng ti ln hn nh mc my pht b st p hoc b chy cun dy phn ng.

i vi my pht in xoay chiu th cng sut nh mc thng ghi gi tr l KVA, trong c cng sut tc dng ( P ) v cng sut phn tc dng ( Q )

P = .U.I. Cos( (6.13 )

Q = .U.I.Sin(

P: cng sut tc dng ca my pht, cng chnh l cng sut ca ng c lai my v cng l cng sut ca cun dy phn ng.

Q: cng sut phn tc dng ca my pht, cng chnh l cng sut ca cun dy kch t.

Thng cng sut nh mc c gi tr: 20KVA, 45KVA, 100KVA.v.v tu thuc vo yu cu tiu th in nng ca mi con tu c th.

e.Tn s nh mc ca my pht in xoay chiu ba pha ( fm )

Thng s ny rt quan trng, bit c tn s nh mc dng cho ti xoay chiu tng ng, thng s ny cng ni nn c tc quay nh mc ca my pht hay tc quay nh mc ca ng c lai my pht, da vo cng thc :

n = ( 6.14 )

Thng tn s ch c 2 gi tr nh mc sau: 50Hz hoc 60Hz

f.Cp cch in ca my pht

Cp cch in l gi tr in tr ca cun dy Rto v cun dy Stato so vi v, i vi cun dy Rto thng cp cch in t: 0.5 M(, 1 M( .v. v i vi cun dy Stato cp cch in thng t: 1 M(, 1.5 M(, 2 M( .v.v 2.4.Phng php u dy ca my pht in xoay chiu ba pha

a.u hnh sao ( Y )+S H-6.10 Khi ng ti ba pha i xng ta c

Quan h dng in v in p

nh sau:+Kt qu

Cn c vo mch in ta thy

quan h gia dng in dy ( Id ) v dng in

pha ( Ip ) nh sau:Id = Ip ( 6.15 )

Quan h gia in p dy ( Ud ) v

in p pha ( Up) nh sau:

Chng minh: AB = 2.OA.Cos30 = 2.OA. =.OA

Trong AB l in p dy ( Ud )

OA l in p pha ( Up)

Vy : Ud =. Up ( 6.16 )

b.u hnh tam gic (( )

+S H-6.11

+Kt qu

Ta c quan h dng in v in

p nh sau:

Quan h in p:Ud = Up (6.17 )

Quan h dng in:

IA = 2.IAB.Cos30 = 2.IAB. = . IAB ( 6.18 )

Trong :

IAB: l ng in pha (Ip)

IA: l ng in dy (Id)

Vy ta c : Id = . Ip ( 6.19 )2.5. S dng, chm sc my pht in ba pha

a.S dng

m bo tnh kinh t th ta phi s dng my pht in xoay chiu ba pha mt cch hp l:

Ti s dng cho my pht lun lun bng hoc nh hn nh mc, bng nh mc l kinh t nht: khng s dng qu ti tc dng ( P ) trnh hin tng chy cun dy phn ng, khng s dng qu ti cng sut phn tc dng ( Q ) trnh qu ti cun dy kch t .

H s Cos( ca ti ti thiu cng phi bng h s Cos( nh mc ca my pht nu ln hn cng tt.

b.Chm sc my pht in ba pha

Thng xuyn lau chi sch s khng du, m, nc bn vo my pht.

Kim tra chi than, nu b mn qu 1/3 th phi thay mi, nu b mt tip xc ca chi vi vnh trt khng tt th phi r chi than.

Kim tra gi chi than, cc bt dy, lc nn ca l xo phi m bo tt.

Thng xuyn o cch in ca rto v stato vi v, nu cch in thp th ta phi em sy my pht .

Kim tra bc n c thiu m hay khng, nu thiu th ta phi bm thm.

III-Phng php iu chnh in p ca my pht in mt chiu

Da vo cng thc (6.4) ta thy mun iu chnh in p ca my pht in ta c 2 phng php:

-Thay i tc quay ca ng c s cp lai my pht.

-Thay i t thng kch t bng cch thay i in tr mch kch t.

Di tu thng s dng phng php thay i t thng kch t, y l phng php ti u nht.HOT NG II : NGHE GII THIU V XEM TRNH DIN MU

-Cu to, nguyn l lm vic v ng dng ca my pht in mt chiu

-Cu to, nguyn l lm vic v ng dng ca my pht in xoay chiu ba pha

-Cc phng php u dy my pht in xoay chiu ba pha

-So snh s khc nhau gia my pht in mt chiu v my pht in xoay chiu trn m hnh thc t



1Tho v nhn bit cc cu to my pht in mt chiuMy pht in mt chiu, ngh tho my phtTho v rp theo quy trnh, trnh by tng chi tit cu to trn m hnh thc t

2Tho v nhn bit cc cu to my pht in xoay chiu ba phaMy pht in xoay chiu ba pha, ngh tho my phtTho v rp theo quy trnh, trnh by tng chi tit cu to trn m hnh thc t

3u dy v chy th my pht in trong hai trng hp : u hnh sao v hnh tam gicMy pht c 06 u dy, ng c lai, dy in, ng h o vn u dy, chy my pht trong hai trng hp, o v a ra nhn xt

D-CU HI NGHIN CU

-Trnh by cc i lng c bn trong mch in

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : MY PHT IN

M bi : MD-M3-B6

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by s khc nhau gia my pht in mt chiu v my pht in xoay chiuMy pht in mt chiu gm 3 phn chnh, my pht in xoay chiu gm 2 phn chnh

2Nu cc phng php u dy my pht in xoay chiu ba phaNu ra s khc bit v ng dng ca phng php u hnh sao v hnh tam gic

Bi 7 : MY BIN P

M bi : MD-M3-B7

A-MC TIU THC HIN-Hiu c cu to v nguyn l hot ng ca my bin p mt pha-Hiu c cu to v nguyn l hot ng ca my bin p ba pha

-Bit c ng dng ca cc loi my bin p, bin dng di tu thy

-u ni v s dng cc my bin p, tho v v sinh, lp rp cc my bin p

B- CC NI DUNG CHNH-Cu to ca my bin p mt pha

-Nguyn l hot ng ca my bin p mt pha-H s ca my bin p

-My bin p ba pha

-My bin dng

-ng dng ca my bin p v my bin dng

C-CC HOT NG HC TP


I-Cu to ca my bin p mt pha

1.1.Li thp l mch t ca bin p

c ghep bang cac la thep ky thut in, cc l thp ny ghp cch in vi nhau sau p cht v st nhau.

Cc l thp ny p cht bi inh c, cng p cht th my bin th cng hot ng tt v t ting n. Thng th cc l thp c ghp li thnh khung kn v c dng hnh ch nht.

1.2.Cun dy my bin p

My bin p v c bn th n c hai cun dy ( my bin p mt pha ) cun s cp ly in vo cn cun th cp ly in ra.

Cun dy l mch in ca my bin p, thng c lm bng ng hoc Nhm tu thuc vo cng sut ca my bin p, cun dy cch in vi li thp bng ba Cc - tng, hoc vi si tm du.

II-Nguyn l hot ng

2.1.S (H-7.2)2.2.Nguyn l hot ng

My bin p hot ng theo nguyn l cm ng in t:

Gi s cun dy s cp c s vng dy lW, cun dy th cp c s vng dy l W. a in p xoay chiu U vo cun dy s cp, lc ny c dng in I, dng in ny sinh ra t thng ( bin thin trong li thp, t thng ny mc vng qua cun dy th cp lm xut hin trong cun dy th cp mt in p cm ng U. Ni hai u cun dy th cp vi ti s xut hin dng in xoay chiu I.

2.3.H s ca my bin p

Ta c cng thc quan h gia s cp v pha th cp ca my bin p nh sau:

y cng chnh l cng thc ca h s my bin p :

k = = = ( 7.1 )

Trong :

k: H s bin p. U: in p s cp. I: Dng in s cp. W: S vng dy ca cun dy s cp. U: in p th cp. I: Dng in th cp. W: S vng dy ca cun dy th cp.

+ Nhn xt: Qua cng thc h s bin p:

k > 1 bin p gi l tng p khi U > U

k < 1 bin p gi l h p, khi U> U

Dng in trong my bin p bao gi cng t l nghch vi in p.

2.4.My bin p ba pha

bin i in p ca mt ngun p ba pha, ta c th dng hai cch:

- T my bin p ba pha, gm ba my mt pha (hnh 7.3a).

- My bin p ba pha, vi li thp ba tr (hnh 7.3b).

a) b)

My bin p 3 pha a) T my bin p 3 pha. b) My bin p ba pha ba tr

Dy qun s cp ca ba pha c k hiu ln lt l AX, BY, CZ

Dy qun th cp ca ba pha c k hiu ln lt l ax, by, cz

Cc cch u dy my bin p pha.

Cc cch du dy

Nu s cp u sao v th cp u sao; ta k hiu Y-Y.

Tng t, ta c 4 cch u c bn:sao - sao Y-Y, sao - tam gic Y-(, tam gic - tam gic (-( v tam gic - sao (-Y.

Nu pha u sao c dy trung tnh, ta k hiu Y0:

Cc cch u dy c bn c v trn hnh (7.4).

2.5.My bin dng

a.Cu to

My bin dng c cu to ging nh my bin p, n cng c cun y v li thp t.

Li thp t p bng cc l thp k thut in.

- Cun dy gm 2 cun: cun s cp c s vng dy t nhng tit din dy ln, cun th cp c tit din dy nh nhng s vng dy ln.

iu c bit l cun s cp ca bin dng c ni ni tip vi ti, hin nay thng dng 2 loi bin dng: loi c cun dy s cp v loi khng c cun dy s cp:- Cu to ca loi c cun dy s cp:

Loi ny cun dy s cp ni ni tip vi ti (H-7.5)

- Cu to ca loi khng c cun dy s cp:

Loi ny li thp t c dng hnh trn khp kn, khng c cun dy s cp m cun dy s cp ch l mt vng dy i xuyn qua li thp, vng dy ny c dng in ti (H-4.19).b.Nguyn l hot ng

Cun dy s cp c s vng dy rt t c u ni tip vi ti, nu l loi khng c cun dy s cp th cho dy in c dng ti i xuyn vo trong lng bin dng. My bin dng hot ng theo nguyn l cm ng in t, cun th cp ca my bin dng nu khng a tn hiu vo mch o hoc x l tn hiu th n phi u ni ngn mch.My bin dng hot ng trong ch ngn mch tn hiu dng in a vo cun s cp sinh ra t thng mc vng qua cun dy th cp lm xut hin trong cun th cp mt sc in ng, sc in ng ny c a ti mch o hoc mch iu khin.III-ng dng ca my bin p v my bin dng

bin i in p ca ngun in xoay chiu t in p cao xung in p thp, hoc t in p thp ln in p cao ta dng my bin p hay cn gi l my bin th. Ngy nay do vic s dng in nng pht trin rng ri nn c nhng loi my bin p khc nhau: my bin p mt pha, 2 pha, hai dy qun, ba dy qun..v . v

My bin p l loi my in xoay chiu lm vic theo ngun l cm ng in t, dng bin bin i in p ca h thng in xoay chiu nhng vn gi nguyn tn s ( f ).

My bin p c vai tr rt quan trng trong h thng in, dng truyn ti v phn b in nng. in p t ngun ti cc ph ti khc nhau, c cp in p khc nhau buc phi s dng my bin p c cc cp in p khc nhau ph hp vi tng i tng ti. Ngoi ra nng cao kh nng truyn ti v gim tn hao cng sut trn ng dy phi gim dng in trn ng dy bng cch nng cao in p nh mc.

My bin p cn c s dng trong cc thit b l nung, bin p hn

HOT NG II : NGHE GII THIU V XEM TRNH DIN MU

-Da trn m hnh thc t, trnh by cu to ca my bin p mt pha v my bin p bap ha-Phng php u dy my bin p mt pha v bap ha.-Phn bit gia bip p v bin dng



1Trnh by cu to ca my bin p mt phaMy bin p mt phaKim tra trn m hnh thc t v nu cu to

2Trnh by cu to ca my bin p ba phaMy bin p ba phaKim tra trn m hnh thc t v nu cu to

3Phn bit s khc nhau gia bin p mt pha v bin p ba phaMy bin p ba pha v my bin p mt phaXem xt hai m hnh ca 02 my bin p v a ra kt lun

D-CU HI NGHIN CU

-E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : MY BIN PM bi : MD-M3-B7H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by cu to my bin p mt phaBao gm cun dy v li thp t

2So snh s khc nhau v cu to v ng dng gia my bin p mt pha v my bin p ba phaKhc nhau v s cun dy v cng sut s dng

Bi 8 : NG C IN MT CHIU

M bi : MD-M3-B8A-MC TIU THC HIN-Hiu c cu to v ng dng ca ng c in mt chiu di tu thy

-Hiu nguyn l hot ng ca ng c in mt chiu di tu thy

-Hiu v ng dng c tnh cht thun nghch my in mt chiu

-u v chy ng c, tho rp v v sinh khi ng c c cch in thpB- CC NI DUNG CHNH-Cu to ca ng c in mt chiu-Tnh cht thun nghch gia my pht v ng c in mt chiu

-Nguyn l hot ng ca ng c in mt chiu-Phn loi ng c in mt chiu

C-CC HOT NG HC TP


I-Cu to ca ng c in mt chiu

Nh phn trn ta bit my in mt chiu c tnh cht thun nghch do ng c in mt chiu cng c cu to ging nh my pht in mt chiu. Vn ch n tiu th ngun nng lng g v n sn sinh ra ngun nng lng g?

My pht bin c nng thnh in nng cn ng c bin in nng thnh c nng. Vy ng c in mt chiu hot ng ta phi c ngun nng lng in mt chiu cp cho my in mt chiu.

Mc d vy nhng rto ca ng c in mt chiu bao gi cng c cu to vng chc hn rto ca my pht in mt chiu do rto ca ng c phi ko ti nng. a.R to

II-Tnh cht thun nghch gia my pht v ng c in mt chiu

My pht in mt chiu v ng c in mt chiu u c th gi chung l my in mt chiu, tnh cht thun nghch ca my in mt chiu l n c th bin ngun in nng mt chiu thnh c nng hoc n c th bin c nng thnh ngun in nng mt chiu. Tc l my in mt chiu c th l ng c in mt chiu v cng c th dng l my pht in mt chiu v vy ngi ta c h thng my pht ng c trong dng in bin i thun nghch t my pht sang ng c hoc t ng c sang my pht.

Nh hnh H-8.2 ta thy nu trc Rto ca my in mt chiu s 1 ( ) c ni vi trc ca ng c Diesel th khi my in mt chiu s 2 ( ) l ng c, nu trc Rto ca my in mt chiu s 2 m ni vi trc ca ng c Diesel th my in mt chiu s1 tr thnh ng c in mt chiu. III-Nguyn l hot ng ca ng c in mt chiuDng in mt chiu i vo cun dy kch t ( cun dy stato ) ca ng c, dng in ny sinh ra t thng chnh trong mch. Nh trn hnh v chiu ng cm ng t B i t trn xung di. Dng in mt chiu i trong cun dy phn ng( cun dy rto ) nm trong t trng ca cun dy stato nn n chu tc dng ca lc in t, lc in t ny xc nh theo quy tc bn tay tri. Nh trn hnh v ta xc nh c chiu ca cm ng t B, chiu dng in chy trong cun dy phn ng v chiu ca lc in t. Hnh H-8.3.

Gi s ti thi im m ta ang xt cun dy phn ng ca ng c in mt chiu c hai thanh tc dng ct t trng ca cun dy kch t, hai thanh ny chu tc dng ca hai lc in t, hai lc ny cng phng cng ln nhng ngc chiu nn n to thnh cp ngu lc lm cho cun dy r to quay. Nhng v cun dy c t c nh trong rnh r to nn n lm r to quay theo.

Tng t nh vy tt c cc thanh ca cun dy r to ln lt chu tc dng ca t trng kch t v chng quay trn u.

Mt iu t ra l khi khung dy phn ng quay c na vng th sao? Ti thi im ny do t trng ca cun dy kch t khng i nn khi thanh pha di o chiu cho thanh pha trn nhng cp ngu lc vn khng o chiu v chiu quay ca ng c khng thay i.

T nguyn l hot ng c bn ca ng c ta c th bit c ng c in mt chiu o chiu quay khi no? Mun o chiu quay ca ng c ta ch c th thay i mt trong hai iu kin: hoc o chiu ca t trng kch t hoc l o chiu ca dng in phn ng. Nu ta ng thi o chiu c t trng kch t v chiu dng in phn ng th ng c khng o chiu quay ( y l iu rt c bit ca ng c in mt chiu )IV-Phn loi ng c in mt chiu

Cng nh my pht in mt chiu, ng c in mt chiu cng c 3 loi:

+ng c in mt chiu kch t song song

+ng c in mt chiu kch t ni tip

+ng c in mt chiu kch t hn hp

Di tu thu thng s dng loi ng c in mt chiu kch t ni tip lm ng c khi ng Diesel, nn ta xt s v c im ca n nh sau:Cun dy kch t ni tip ca my pht in mt chiu kch t ni tip c ni ni tip vi cun dy phn ng, v vy dng in phn ng cng chnh l dng kch t, Dng in khi ng c th gp (5-7) ln dng nh mc, nn m men khi ng ca ng c in mt chiu rt ln (Nghin c phn sau).HOT NG II : NGHE GII THIU V XEM TRNH DIN MU-Xem s v m hnh thc t nhn bit cu to cu ng c in mt chiu-Xem s nhn bit tnh cht thun nghch my in mt chiu

-Phn tch v a ra s nhn bit v nguyn l hot ng ng c in mt chiu



1Tm hiu cu to ng c in mt chiung c in mt chiu v ngh tho rp ng cTho v rp ng c in mt chiu theo quy trnh. Nhn bit cu to cc b phn ca ng c

2Chy th my pht in v kim tra thng s cng nh cch iu chnh v o chiu quayng c in mt chiu v ngun in mt chiu, bin tr mch kch tu ni v chy th ng c, o chiu quay ng c, iu chnh tc quay ca ng c

D-CU HI NGHIN CU

-Nu cu to ng c in mt chiu-Nu ng dng ca ng c in mt chiu di tu thy

-Trnh by tnh cht thun nghch my in mt chiu

-Trnh by nguyn l hot ng ca ng c in mt chiu

E-NI DUNG PHIU KIM TRA DNH GI THC HINBi : NG C IN MT CHIU

M bi : MD-M3-B8

H v tn hc sinh:

TTNI DUNGS LIU

KIM TRAYU CU

K THUTNH GI

BP X L

1Trnh by cu to ng c mt chiuNu bt cu to gm my phn chnh

2Trnh by v tnh cht thun nghch my in mt chiuNu tnh cht v ng dng ca tnh cht ny

Bi 9 : NG C KHNG NG B BA PHA

M bi : MD-M3-B9

A-MC TIU THC HIN-Hiu c cu to v ng dng ca ng c khng ng b ba pha di tu thy

-Hiu nguyn l hot ng ca ng c khng ng b ba pha

-Nm c hai phng php u dy v ng dng ca tng phng php ngoi thc t

-u ni hot ng ng c, u ni o chiu quay ng c. Tho v sinh v lp rp ng c in xoay chiu ba phaB- CC NI DUNG CHNH-Cu to ng c khng ng b ba pha rto lng sc-Kho st t trng dng in ba pha

-Nguyn l hot ng ca ng c khng ng b ba pha.-Phng php u y ca cun dy Stato-Phng php o chiu quay v khi ng ng c khng ng b ba pha Rto lng sc.

C-CC HOT NG HC TP


I-Cu to ng c khng ng b ba pha rto lng sc

1.1.Stato

Bao gm: v my c c bng gang, li thp t c hnh tr c ghp bng cc l thp k thut in, trn c phay thnh cc rnh. Dy qun c th c lm bng ng hoc bng Nhm v c sn ph cch in.(H-4.8)

1.2.Rto lng sc (Dng thanh dn bn trong rto c hnh nh H-9.2).

Li thp t : c hnh tr gm nhiu l thp k thut in ghp st cch in vi nhau, trn b mt li thp c c cc l xuyn dc Rto, li thp c gn cht vi trc ng c. Trong cc l ngi ta nhm hoc ng cn bn ngoi c ni kn bi 2 vng trn ngn mch 2 u.

II-Kho st t trng dng in ba pha

2.1.S H-9.3

2.2Kt lun

Cho dng in ba pha vo ba cun dy t lch nhau 120 in ca stato ng c khng ng b ba pha, gi s trong mt chu k t trng nh hnh v:

+ V tr 1: Pha A dng,

+ V tr 2: Pha B dng,

+ V tr 3: Pha C dng.

Chng t t trng dng in ba pha l t trng quay. V vy ng c in xoay chiu ba pha khi a dng in ba pha vo ba cun dy stato ta c t trng trong n l t trng quay. Kt lun rng ng c in xoay chiu ba pha c m men t khi ng m khng phi dng bin php khi ng nh ng c in xoay chiu mt pha ( T trng ca dng mt pha l t trng p mch nn ng c xoay chiu mt pha khng c m men t khi ng m ta phi dng bin php khi ng ). y l tnh cht quan trng ca ng c in xoay chiu ba pha.

T s kho st t trng ba pha ta rt ra kt lun quan trng na l : o chiu quay ca t trng ta ch cn o hai trong ba pha ca ngun in . y l tnh cht c bit dng o chiu quay ca ng c ba pha sau ny.III-Nguyn l hot ng ca ng c khng ng b ba pha.

3.1. trt ( s )

Do tc quay ca Rto phi nh hn tc quay ca t trng ( n < n). V nu bng th t trng quay khng ct cun dy Rto nn sc in ng trong thanh dn Rto bng 0 v t m men quay c gi tr bng 0, Rto khng quay.

Do tc quay ca t trng v tc quay ca Rto khng bng nhau nn ta c trt s tnh theo cng thc:

S = ( 9.1)

Tc quay ca t trng quay v tc quay ca rto khng bng nhau nn ng c cn c gi l ng c khng ng b ba pha.

3.2.S

Ba cun dy stato AX, BY, CZ t lch

nhau 120in.

F : Lc in t

Ic : Dng in cm ng trong thanh dn rto.

n : Tc

khÍ cỤ ĐiÊn

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