lecture 8: flyback example -...
TRANSCRIPT
Lecture 8: Flyback Example
ECE 481: Power ElectronicsProf. Daniel Costinett
Department of Electrical Engineering and Computer Science
University of Tennessee Knoxville
Fall 2013
Flyback Converter Example
Vcell
Lm
1:n
Cout
S1
Vbat
+
_
Ib1
Ic1
S2
+
_
Vg
V
Equivalent Circuit Model
n
VDDVv glm
'0R
V
n
IDi lm
co '0lmg DIi
Large Step Conversion Ratio
Boost Converter
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10
50
100
150
200
250
300
350
400
450
500
V/V
g
D
Flyback, n=100
RL/n2R=0.1
RL/n2R=0.05
RL/n2R=0.02
RL/n2R=0.01
RL/n2R=0.005
Flyback Semiconductor Waveforms
t
t
Vcell
Lm
1:n
Cout
S1
Vbat
+
_
Ib1
Ic1
S2
+
_
Vg
V
Flyback Switch Implementation
Vcell
Lm
1:n
Cout
S1
Vbat
+
_
Ib1
Ic1
S2
+
_
Vg
V
Flyback Reverse Recovery
t
t
Flyback Reverse Recovery
t
t
Flyback Reverse Recovery
s
rlm
s
rlmg T
QI
T
tDIi
n
VDDVv glm
'0
s
rlm
s
rlmco nT
QI
nT
t
R
V
n
IDi '0
