Bcl Cau 1pha 4
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Transcript of Bcl Cau 1pha 4
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8/14/2019 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
BI GING IN TCNG SUT Page 30
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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 31
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
BI GING IN TCNG SUT Page 32
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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 33
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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 34
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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
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
BI GING IN TCNG SUT Page 35
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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 36
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.
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TS. L MINHPHNG [CH U RECTIFIER]NG III : B CHNH L
BI GING IN TCNG SUT Page 37
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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 38
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.
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TS. L MI NG [CHNG III : B CHNH LU RECTIFIER]NHPH
BI GING IN TCNG SUT Page 39
]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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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 40
Us(V)
Ud(V)
i1(A)
iT1(A)
UT1(V)
T1D2
iT1
iT4
T3D4 T1D2D2D3 D2D3 D3D2
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TS. L MINHPHNG [CHNG III : B CHNH LU RECTIFIER]
BI GING IN TCNG SUT Page 41
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
=
-
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TS. L MI NG B CH U RECTIFIER]NHPH [CHNG III : NH L
BI GING IN TCNG SUT Page 42
=
-
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TS. L MINHPHNG [CHNG III : U RECTIFIER]B CHNH L
BI GING IN TCNG SUT Page 43
-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.