rectificadores no controlados.ppt
TRANSCRIPT
04/08/23 EEL 4242 by Dr. M.H. Rashid 1
EEL 4242POWER ELECTRONICS
RECTIFICADORES CON DIODOS
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Rectificadores Monofásicos de Media Onda
( ) 0
( )
2 2( ) 0
( )
1sin
2
1sin
2 2
2
mo dc m
mo dc
mo rms m
mo rms
VV V d
VI
R
VV V d
VI
R
Figure 3.1
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Formsa de Onda de Entrada
2 2
2
21 1
dc dc dc ac rms rms
dcac rms dc
ac
rms ac
dc dc
rms
dc
P V I P V I
PV V V
P
V VFF RF
V V
VRF FF
V
Figure 3.2
22 21
21 1
1 1
( )
cos
1
cos cos
dc
s s
s s s
s s
s S S
s S S
S peak
S
PTUF DF
V I
I I IHF
I I
V I IPF
V I I
ICF
I
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Rectificador de M.O. Con Carga RLFigure 3.3
( ) 0
( )
1sin
2
1 cos2
1 cos2
o dc m
m
mo dc
V V d
V
VI
R
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Rectificador O.C. (Tap-central)
Figure 3.5
( ) 0
( )
2 2( ) 0
( )
22sin
22
2sin
2 2
2
mo dc m
mo dc
mo rms m
mo rms
VV V d
VI
R
VV V d
VI
R
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Full-Wave Bridge Rectifier
Figure 3.6
( ) 0
( )
2 2( ) 0
( )
22sin
22
2sin
2 2
2
mo dc m
mo dc
mo rms m
mo rms
VV V d
VI
R
VV V d
VI
R
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Bridge Rectifier (motor load)
Figure 3.7
1
4 sin sin 3 sin 5( ) ....
1 3 5
40.90
2
as
as a
I t t ti t
II I
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Bridge Rectifier (RL load)
Figure 3.8
2 sin 0oo s o
diL Ri E V t for idt
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Bridge Rectifier (RL load)
( / )1
22 1
2 sin 0
2sin
tan ( / )
oo s o
R L to
diL Ri E V t for idt
V Ei t Ae
Z R
Z R L L R
• Case 1: Continuous conduction, Io >0
• Case 2: Discontinuous conduction, Io =0
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Bridge Rectifier (RL load)
( / )( / )( / )
0
2 2sin
1
0 0
R L to R L
V Ei t e
Z e R
for t and i
• Case 1: Continuous conduction, Io >0
• Case 2: Discontinuous conduction, Io =0
( / )( / )
0
1
tan
2 2sin sin
0
sin , ( ) 0
sin sin 0cos cos
R L to
om
V E V Ei t e
Z R Z R
for i
EAt t i t
V
x xe
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Boundary of continuous and discontinuous (single-phase)
Figure 3.9
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Multiphase Rectifiers
Figure 3.12
/ 2 2( ) 0
2cos
2 /
1 2sin
2 2
q
o rms m
m
V V dq
qV
q q
/
( ) 0
2cos
2 /
sin
q
o dc m
m
V V dq
qV
q
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Three-Phase Bridge Rectifier
Figure 3.13
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Waveforms and Conduction Times
/ 6
( ) 0
23 cos
2 / 6
3 31.654
o dc m
m m
V V d
V V
Figure 3.14
/ 2 2( ) 0
23 cos
2 /
3 9 31.6554
2 4
q
o rms m
m m
V V dq
V V
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3-Phase Bridge Rectifier (RL Load)
Figure 3.15
22 sin
3 3
2 sin 0
ab ab
oo ab o
v V t for t
diL Ri E V t for idt
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Three-Phase Bridge Rectifier (RL load)
( / )1
22 1
2 sin 0
2sin
tan ( / )
oo ab o
R L tabo
diL Ri E V t for idt
V Ei t Ae
Z R
Z R L L R
• Case 1: Continuous conduction, Io >0
• Case 2: Discontinuous conduction, Io =0
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Three-Phase Bridge (RL load)
( / )( /3 )( / )( /3 )
0
sin 2 / 3 sin / 32sin
1
/ 3 2 / 3 0
R L tabo R L
V Ei t e
Z e R
for t and i
• Case 1: Continuous conduction, Io >0
• Case 2: Discontinuous conduction, Io =0
( / )( /3 )
( / )( /3 )
( )2 tan
( )2 tan
0 ( .3.47)
sin 2 / 3 sin / 320
1
sin 2 / 3 sin / 3( ) cos
21
o
R Lab
R L
ab
Setting I in Eq
eV E
Z e R
eEx
Ve
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Boundary of continuous and discontinuous (three-phase)
Figure 3.16
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DC Filters
Figure 3.18
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AC Filters
Figure 3.19
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Single-Phase Rectifier with C-Filter
Figure 3.22
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Single-Phase Rectifier with C-Filter
Figure 3.22
( )
( )( )
( )
( )
4
2 2 4 2
1
2(4 1)
mo dc m
e
r pp mrms ripple
e
rms ripple
o dc e
VV V
fRC
V VV
fRC
VRF
V fRC
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Output Voltage with C-Filter
Figure 3.26
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Effects of Source Inductances
Figure 3.27
1 2 3
1 2 3
2 ( )
6x dc
dc
V f L L L I
fLI if L L L
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Summary
• What was the major idea?
• What was the muddiest idea?
• Diode rectifiers convert an ac voltage to a dc voltage. • The output voltage contain ripples which can be removed by filters. • Depending on time constant of the load, the load current may be discontinuous. • Line inductances cause overlap and reduce the effective dc output voltage.