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2011-10-27 1 Secondary Rectifier For Buck-Derived Converters Presented by Xinbo Ruan Aero-Power Sci-tech Center Nanjing University of Aeronautics & Astronautics
Transcript of Secondary Rectifier For Buck-Derived Convertersruanxb.nuaa.edu.cn/Home/Ruan...
2011-10-27 1
Secondary Rectifier For Buck-Derived Converters
Presented by
Xinbo Ruan
Aero-Power Sci-tech CenterNanjing University of Aeronautics & Astronautics
2011-10-27 2
Full-wave, Full-Bridge and Current Doubler Rectifier
Full-Wave Full-Bridge
Current Doubler Rectifier
2011-10-27 3
Half-Wave Rectifier
vrect
0
vrect
0
sec_
ohalf
m
VD
V=
Positive cycle
Negative cycle
2011-10-27 4
Tr
*
Lf
Cf
RLd
Vovrect
iLf
Derivation of Full-Wave Rectifier
Positive cycle
Negative cycle
Two rectifiers with two coupled windings share the filter.
2011-10-27 5
*
Lf
Cf
RLdTr
*Vovrect
iLf vrect
0
vrect
0
Derivation of Full-Wave Rectifier
2011-10-27 6
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
Operation Principle of Full-Wave Rectifier (1)
*
Lf
Cf
RLdTr
*Vovrect
iLfDR1
DR2
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*
Lf
Cf
RLdTr
*Vovrect
iLfDR1
DR2
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
Operation Principle of Full-Wave Rectifier (2)
2011-10-27 8
*
Lf
Cf
RLdTr
*Vovrect
iLfDR1
DR2
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
Operation Principle of Full-Wave Rectifier (3)
2011-10-27 9
*
Lf
Cf
RLdTr
*Vovrect
iLfDR1
DR2
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
Operation Principle of Full-Wave Rectifier (4)
2011-10-27 10
1 2 sec_2DR DR mV V V= =
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
Relationships of Full-Wave Rectifier
sec_
2oeq half
m
VD D
V= =
1 212DR DR oI I I= =
Inductor current can not flow in the negative direction.
*
Lf
Cf
RLdTr
*+
_
Vo
+
_vrect
iLfDR1
DR2
2011-10-27 11
Tr
*
Lf
Cf
RLd
Vovrect
iLf
Derivation of Full-Bridge Rectifier (1)
Positive cycle
Negative cycle
Two rectifiers share both the winding and the filter.
2011-10-27 12
Tr
*
Lf
Cf
RLd
Vovrect
iLf
Derivation of Full-Bridge Rectifier (2)
2011-10-27 13
vrect
0
vrect
0
Derivation of Full-Bridge Rectifier (2)
2011-10-27 14
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
iDR4 iDR3
Operation Principle of Full-Bridge Rectifier (1)
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Operation Principle of Full-Bridge Rectifier (2)
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
iDR4 iDR3
2011-10-27 16
Operation Principle of Full-Bridge Rectifier (3)
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
iDR4 iDR3
2011-10-27 17
Operation Principle of Full-Bridge Rectifier (4)
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
iDR4 iDR3
2011-10-27 18
1 2 sec_DR D mRV VV= =
Relationships of Full-Bridge Rectifier
sec_
2oeq half
m
VD D
V= =
1 212DR DR oI I I= =
Inductor current can not flow in the negative direction.
t
t
vrect
Ts/2 Ts
0
0
iLf
vsec
0
t
tiDR1
0
Vsec_m
VoVsec_m
Io
iDR2
iDR4 iDR3
2011-10-27 19
Lf
Cf
RLd
Tr
*
Vovrect
iLf
Lf
Cf
RLdTr
*Vovrect
iLf
Derivation of Current-Doubler Rectifier (1)
Positive Cycle
2011-10-27 20
Lf
RLd
Tr
*
Cf
_
+
vrect
iLf
+
_
Vo
Lf
Cf
RLd
Tr
* _
+
Vo
_
+
vrect
iLf
Derivation of Current-Doubler Rectifier (2)
Negative Cycle
2011-10-27 21
Derivation of Current-Doubler Rectifier (3)
sec_
ohalf
m
VD
V=
Two rectifiers share the winding and filter capacitor.
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t
0
iLf1
vsec
0
t
t
iDR1
0
Vsec_m
Io
Io/2iLf2
Ts/2 Ts
t0
iDR2
io
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
Operation Principle of Current-Doubler Rectifier (1)
2011-10-27 23
t
0
iLf1
vsec
0
t
t
iDR1
0
Vsec_m
Io
Io/2iLf2
Ts/2 Ts
t0
iDR2
io
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
Operation Principle of Current-Doubler Rectifier (2)
2011-10-27 24
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
Operation Principle of Current-Doubler Rectifier (3)
t
0
iLf1
vsec
0
t
t
iDR1
0
Vsec_m
Io
Io/2iLf2
Ts/2 Ts
t0
iDR2
io
2011-10-27 25
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
Operation Principle of Current-Doubler Rectifier (4)
t
0
iLf1
vsec
0
t
t
iDR1
0
Vsec_m
Io
Io/2iLf2
Ts/2 Ts
t0
iDR2
io
2011-10-27 26
Lf
RLd
Tr
*
Cf
iLf2
+
_
Vo
Lf
iLf1
DR2
DR1
1 2 sec_DR D mRV VV= =sec_
ohalf
m
VD
V=
1 212DR DR oI I I= =
Relationships of Current-Doubler Rectifier
t
0
iLf1
vsec
0
t
t
iDR1
0
Vsec_m
Io
Io/2iLf2
Ts/2 Ts
t0
iDR2
io
2011-10-27 27
t
0
vsec
0
t
t
iDR1
0
Vsec_m
Ts/2 Ts
t0
iDR2
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
iLf1Io/2
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
DCM of Current-Doubler Rectifier (1)
iDR1
0
0
iDR2
Inductor current can flow in the negative direction.
2011-10-27 28
Lf2
RLd
Tr
*
Cf
iLf2
Vo
Lf1
iLf1
DR2
DR1
io
t
vsec
0
t
t
iDR1
0
Vsec_m
Ts/2 Ts
t0
iDR2
DCM of Current-Doubler Rectifier (2)
2011-10-27 29
DCM of Current-Doubler Rectifier (2)
Lf
RLd
Tr
*
Cf
iLf2
Vo
Lf
iLf1
DR2
DR1
Inductor current can flow in the negative direction.
t
Ts/2 Ts
0
vsec
0
t
t
0
Vsec_m
iDR1 iDR2Lf
RLd
Tr
*
Cf
iLf2
Vo
Lf
iLf1
DR2
DR1
2011-10-27 30
Comparison of Reectifiers (1)
Design a DC/DC converter
Input Voltage: Vin
Output Voltage: Vo
Output Current: Io
Given the duty cycle of all the switches be 0.5
2011-10-27 31
Full-Wave
Full-Bridge
CDR
Rectifier Winding Ratio
Current Stress
Voltage Stress
No. of Diodes
Io
Io
Io
2Vin/K02
Total Power of Diodes
4VinIo
4VinIo
4VinIo2Vin/K0 2
4Vin/K0
Topology
*
Lf
Cf
RLdTr
*+
_
Vo
+
_vrect
iLfDR1
DR2
Lf
RLd
Tr
*
Cf
iLf2
+
_
Vo
Lf
iLf1
DR2
DR1
Comparison of Reectifiers (2)
Applica-tions
Low output voltage
High output voltage
Low output
voltage, high
cureent
K0
K0
K0/2
