SLIDE 1
PVMD
Delft University of Technology
Learning objectives
DC-DC converter
- 1. Introduction to electrical conversion
- 2. Electrical components
- 3. Topologies
- 4. Efficiency of a buck-boost converter
PVMD Delft University of Technology Learning objectives DC-DC - - PowerPoint PPT Presentation
PVMD Delft University of Technology Learning objectives DC-DC - - PowerPoint PPT Presentation
Buck-Boost Converter and its Efficiency Olindo Isabella PVMD Delft University of Technology Learning objectives DC-DC converter 1. Introduction to electrical conversion 2. Electrical components 3. Topologies 4. Efficiency of a buck-boost
SLIDE 2
SLIDE 3
Buck-Boost converter
Vout Vin
+
- RL
C VL L
- +
Load
+
- Iout
IL
SLIDE 4
Buck-Boost converter: on
Vout Vin
+
- RL
C VL L
- +
Load
+
- Iout
IL ON Iin
SLIDE 5
Buck-Boost converter: off
Vout Vin
+
- RL
C VL L
- +
Load
+
- Iout
IL OFF Vd~0
SLIDE 6
Continuous mode
See Solar Energy book, Appendix F
0,5 0,25 0,75 1 D Vout Vout Vout Vin
SLIDE 7
Buck Boost Buck-Boost D = 0 Vout = 0 D = 1 Vout = Vin
Comparison
!
"#$ =
& 1 − & !
)*
!
"#$ =
!
)*
1 − & !
"#$ = & + ! )*
Buck Boost Buck-Boost D = 0 Vin = ∞ D = 1 Vin = Vout
!
)* = 1 − &
& !
"#$
!
)* = ! "#$(1 − &)
!
)* = ! "#$
&
Vout = Vin Vout = ∞ Vout = 0 Vout = ∞ Vin = Vout Vin = 0 Vin = ∞ Vin = 0
SLIDE 8
Efficiency of the converter
Pout = output power PD = dissipated power Pswitch = switch losses PL = coil losses
SLIDE 9
Example
Capacitor (C) Voutput MOSFET, metal-oxide semiconductor field-effect transistor MOSFET Inductor (L)
- +
Vinput
+
- Controller
MOSFET
SLIDE 10