bcl cau 1pha 4

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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]

VII.B CHNH LU CU MT PHA IU KHIN HON TON.1. S.

- Ngun xoay chiu mt pha:

BI GING IN TCNG SUT Page 29

Ud

iT1 iT3

id

tUu m sin=

- Linh kin bn dn: 4 thyistor cng sut

T1,T2 ,T3,T4- Ti mt chiu dng tng qut RLE

iT4 iT2

T1UT1 UT3 T3

T4 UT2 T2

L

R

E

UT4

2. K hiu:

- Dng tc thi qua linh kin SCR cng sut iT1 , iT2 , iT3, iT4- in p trn linh kin SCR cng sut uT1 , uT2 , uT3, uT4- in p v dng in ti ud ,id- Tr trung bnh in p, dng in ti Ud ,Id- Tr hiu dng p pha ngun U- Tr hiu dng dng in ngun I1- Bin in p pha ngun Um

3. Gi thit:- Ngun p l tng: ngun xoay chiu mt pha l tng, in trtrong ca ngun bng

khng.- Cc linh kin bn dn l tng: in p trn linh kin khi dn bng 0.- Ti L ln dng ti phng v lin tc.- Mch trng thi xc lp.

4. Phn tch.- Tng t BCL cu ba pha ta chia thnh hai nhm: nhm Anode (T1, T3) v nhm Cathode(T4, T2). Trong cng mt khong mt thi gian s c hai linh kin ca hai nhm cng dn.a. Xc nh khong dn ca cc SCR

- ][ +]2[

-Linh kin T1, T2 cng dn.- ++

UT1

U1

-Linh kin T3, T4 cng dn.

iT1 iT3

id

T1 UT3 T3

U2

UdA

iT4 iT2

T4 T2UT4 UT2

U1 U2

id

UdK

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TS. L MINHPH ]NG [CHNG III : B CHNH L U RECTIFIER


Gi s ngun xoay chiu mt pha c chia lm hai ngun , :1u 2u

tUm

sin2

=

uu

21= ; (sin

222=

=

Uu m ) tu [ ] + : T1,T2 dn

=

=

dT

T

ii

u

1

10

=

==

03123

T

T

i

uuuu

1uu

dA

=

=

=

T

T

ii

u

2

2 0

=

==

04

124

T

T

i

uuuu 2uudK =

d

tUuuuumd

uudKdA sin21 == = =

[ ] ++ 2 : T3,T4 dn

=

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UT1(V)

UT4(V)

UT3(V)

UT2(V)

Hnh 3.11 Gin in p v dng in qua linh kin

5. H qup chnh lu c dng hai xung trong mt chu k p ngun, BCL c gi l b chnh lu hai

xung. Tn s hi cbn p chnh lu bng 2 ln tn s p ngunHzfpf 10050.2.)1( ===

Trong : p - s xung chnh lu

Tr trung bnh in p chnh lu (in p ti).

cos22

cos2

)(sin1

UUttdUU mmd === +

UUU d

2222Khi 0

- Nh vy b chnh lu cu 3 pha iu khin hon ton c th lm vic ch nghch lu vchuyn nng lng v ngun. N c th lm vic hai gc phn t I v IV

Tr trung bnh dng in chnh lu (dng in ti).

R

EUdId

=

p ngc ln nht m SCR phi chu.

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TS. L MINHPHNG [CH U RECTIFIER]NG III : B CHNH L


mRWMUU == 2U

Dng trung bnh qua SCR.

2... 41

d

TT II ==

I=

- Khi thit k ta phi chn linh kin sao cho :URRM Ku.U RWM v Id Ki ID1

Trong : Ku = 2,5- 3,5 : H s an ton pKi 1 : h s an ton v dng

Tr hiu dng dng in ngun.

dII =1

Cng sut tiu th trn ti.

dddIUP =

H s cng sut ngun b chnh lu.

cos901.022

1

====d

dddd

UI

UI

UI

IU

S

P

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VIII. B CHNH LU CU 1 PHA IU KHIN BN PHN I XNG1. S:

Ud

iT1 iT3

id - Ngun 1 chiu m tUu sin=

- Linh kin gm hai Thyristor cng sut(T1, T3) v hai Diode cng sut (D2,D4).

- Ti mt chiu RLE dng tng qut

iD4 iD2

T1UT1 UT3 T3

D4UD4 UD2 D2

L

R

E

2. K hiu:

- Dng tc thi qua linh kin cng sut iT1 , iD2 , iT3, iD4- in p trn linh kin cng sut uT1 , uD2 , uT3, uD4- in p v dng in ti ud ,id- Tr trung bnh in p, dng in ti Ud ,Id- Tr hiu dng p pha ngun U- Tr hiu dng dng in ngun I1- Bin in p pha ngun Um

3. Gi thit:- Ngun p l tng: ngun xoay chiu mt pha l tng, in trtrong ca ngun bng

khng.- Cc linh kin bn dn l tng: in p trn linh kin khi dn bng 0.- Ti L ln dng ti phng v lin tc.- Mch trng thi xc lp.

4. Phn tch.- Chia thnh hai nhm: nhm Anode (T1,T3) v nhm Cathode (D2,D4). Trong cng mtkhong mt thi gian s c hai linh kin ca hai nhm cng dn.

UT1

U1

iT1 iT3

id

T1UT3 T3

UdA

U2

a. Xc nh khong dn ca cc linh kin.Gi s ngun xoay chiu mt pha c chia lm hai ngun , :

1u

2u

tUu

u m sin221

== ; )(sin222

=

= tUu mu

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Phn tch nhm Anode: T1,T3 :[ ] +- : T1 dn khi kho p trn linh kin dng tc l trong bn phn dng ca in

p ngun 1u

- ][ +2 : T3 dn khi kho p trn linh kin dng tc l trong bn k dng cain p ngun 2u

+

Phn tch nhm Cathode: D2,D4- [ ]0 : D2 dn khi kho p trn linh kin dng tc l trong bn k m ca in p ngun

2u .

- [ ] 2 : D4 dn khi kho p trn linh kin dng tc l trong bn k m ca in p ngun

1u [ ]0 : T3,D2 dn

2u

=

=

0

0

3

3

T

T

i

u

2uudA =

=

=

01

11

T

T

i

uu

==

00

2

2

T

T

iu

= 04Di2uudK = == 124

D uuuu

022 === uuuuu dKdAd

[ ] : T1,T2 dn

=

=

dT

T

ii

u

1

1 0

=

==

03

123

T

T

i

uuuu

1uudA =

=

=

T

T

ii

u

2

2 0

=

==

04

124

T

T

i

uuuu 2uudK =

d

tUuuumd

uuudKdA sin21 == = =

[ ]0 : T1,D4 dn

1u 1uudA =

=

=

0

0

1

1

T

T

i

u

=

=

03

23

T

T

i

uu

=

=

02

212

T

T

i

uuu

= 04Di1uudK =

= 04Du

022

=== uuudK

uudAd

[ ] 2 : T3,D4 dn+

=

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Us(V)

Ud(V)

i1(A)

iT1(A)

UT1(V)

T1D2

iT1

iD4

T3D4 T1D2T3D2 T1D4 T3D2

Hnh 3.13 Gin p chnh lu, p v dng qua linh kin


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UT1(V)

UD4(V)

UT3(V)

UD2(V)

T1D2 T3D4 T1D2T3D2 T1D4 T3D2

Hnh 3.14 Gin p chnh lu, p v dng qua linh kin

5. H qup chnh lu c dng hai xung trong mt chu k p ngun, BCL c gi l b chnh lu hai

xung. Tn s hi cbn p chnh lu bng 2 ln tn s p ngunHzfpf 10050.2.)1( ===

Trong : p - s xung chnh luTr trung bnh in p chnh lu (in p ti).

)cos1(2)cos1()(sin1

+=+== UU

ttdUU mmd

UUd

22Khi 0 0

- Nh vy b chnh lu cu 3 pha iu khin bn phn ch c th lm vic ch chnh lu.N c th lm vic hai gc phn t I

Tr trung bnh dng in chnh lu (dng in ti).

R

EUdId

=

p ngc ln nht m SCR phi chu.

8/14/2019 Bcl Cau 1pha 4

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TS. L MINHPHNG [CH U RECTIFIER]NG III : B CHNH L


mRWMUU == 2U

Dng trung bnh qua SCR.

2... 61

d

DT II ==

I=

- Khi thit k ta phi chn linh kin sao cho :URRM Ku.U RWM v Id Ki ID1

Trong : Ku = 2,5- 3,5 : H s an ton pKi 1 : h s an ton v dng

Tr hiu dng dng in ngun.

= dI1

I

Cng sut tiu th trn ti.

ddd IUP =

H s cng sut ngun b chnh lu.

1UI

IU

S

Pddd

==

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IX. B CHNH LU CU 1 PHA IU KHIN BN PHN KHNG I XNG1. S:

Ud

iT1 iD3

id

E

T1UT1 UD3 D3

T4UT4 UD2 D2

L

R

iT4 iD2

Ngun 1 chiu l tng u tUm sin=

-Linh kin gm hai Thyristor cng sut (T1, T4) vhai Diode cng sut (D2, D3)- Ti mt chiu RLE dng tng qut

2. Gi thit :- Ngun mt pha l tng- Linh kin l tng- Dng ti lin tc v mch trng thi xc lp

1. Phn tch.-Tng t BCL cu ba pha ta chia thnh hai nhm : nhm Anode (T1,T3) v nhmCathode(D4,D2). Trong cng mt khong mt thi gian s c hai linh kin ca hai nhm cng

dn.

tUu

u m sin221

==

)sin(2

tUm

22==

uu

UT1

U1

iT1 iD3

id

T1 UD3 D3

UdA

U2

iT4 iD2

T4 D2UT4 UD2

U1 U2

id

UdK

][ -Linh kin T1,D2 cng dn.-

][ +]2-Linh kin D2,D3 cng dn.-

-[ + - Linh kin D3,T4 cng dn.

8/14/2019 Bcl Cau 1pha 4

11/15

TS. L MI NG [CHNG III : B CHNH LU RECTIFIER]NHPH


]0-[

1uT

- Linh kin D3,D2 cng dn.

Phn tch nhm Anode: T1, D3- T1 dn khi kho p trn linh kin dng tc l trong bn phn dng ca 1u

1123 ;0;0 uuuuuu dAT =

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Us(V)

Ud(V)

i1(A)

iT1(A)

UT1(V)

T1D2

iT1

iT4

T3D4 T1D2D2D3 D2D3 D3D2

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UT1(V)

UD4(V)

UT3(V)

UD2(V)

T1D2 T3D4 T1D2T3D2 T1D4 T3D2

Gin p chnh lu, khong dn cc linh kin

-Trong khong [ ]0 ]2hoc 2[ - D3,D2 dn +

=

>=

0

0

1

1

T

T

i

uu

=

8/14/2019 Bcl Cau 1pha 4

14/15

TS. L MI NG B CH U RECTIFIER]NHPH [CHNG III : NH L


=

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15/15

TS. L MINHPHNG [CHNG III : U RECTIFIER]B CHNH L


-Dng trung bnh qua linh kin Diode dT II

2

+=

- p ngc ln nht qua linh kin URNM 2=U

dII

=1- Tr hiu dng dng ngun

- H s cng sut ngun b chnh luIU

IU dd

.

.=

Nhn xt.- C hai cu hnh u lm mt phn m trn ti v th thun li hn cho cc ng dng- Ch nghch lu khng xy ra- H s cng sut cao hn so vi chnh lu cu 1 pha iu khin hon ton- Thi gian ngt an ton : mch khng i xng an ton hn mch i xng v iu khin

hon ton.

bcl cau 1pha 4

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