Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download SMPS: ISOLATED FORWARD CONVERTER "Non
Document related concepts
Solar micro-inverter wikipedia , lookup
Stepper motor wikipedia , lookup
Electrical ballast wikipedia , lookup
Topology (electrical circuits) wikipedia , lookup
Ground (electricity) wikipedia , lookup
Control system wikipedia , lookup
Immunity-aware programming wikipedia , lookup
Mercury-arc valve wikipedia , lookup
Power engineering wikipedia , lookup
Current source wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Stray voltage wikipedia , lookup
Three-phase electric power wikipedia , lookup
Power inverter wikipedia , lookup
Analog-to-digital converter wikipedia , lookup
Distribution management system wikipedia , lookup
History of electric power transmission wikipedia , lookup
Electrical substation wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Transformer wikipedia , lookup
Alternating current wikipedia , lookup
Voltage optimisation wikipedia , lookup
Voltage regulator wikipedia , lookup
Schmitt trigger wikipedia , lookup
Amtrak's 25 Hz traction power system wikipedia , lookup
Mains electricity wikipedia , lookup
Transformer types wikipedia , lookup
Integrating ADC wikipedia , lookup
Opto-isolator wikipedia , lookup
HVDC converter wikipedia , lookup
Transcript
SMPS: ISOLATED FORWARD CONVERTER
Vds
"Non-isolated SINGLE ENDED STEP-DOWN FORWARD (direct) CONVERTER"
Vind
Ids
Irect
Ei n
Iind Iout
L
ind
Vrect
Vgs
fsw
Iout
IC
C
R
Vout
Irect
limitations of the basic converter:
x single input single output
x no isolation: single ended or common input -output connection
x fixed output voltage polarity : dependent upon topology
x output voltage relative to the input limited to duty cycle control
x 0<D<1;
D0 limited by transistor switching time
solution:
x transformer coupled (isolated) derivations of the basic converter
problem:
x suggests the need for a dc-dc transformer!!!!!
problem:
x suggests the need for a dc-dc transformer!!!!!
solution:
concept:
x introduce the 'concept' of a DC transformer
AC-AC
DC-DC
practice:
E
in(dc)
Vout(dc)
x primary side switching
pulsating input current
x secondary side rectification
F-W in some topologies
sync
x 1-T (1-transistor switch)
low& medium power stages
switch
x 2-T (2-transistor switch)
half off-state voltage per
topologies:
x the 'dc-dc transformer' insertion point in the basic circuit results
in different topology converters
x the need for additional switches and rectifiers depends on the
topology as it is sometimes possible to use the existing basic
circuit elements in a dual role.
EET 423 POWER ELECTRONICS 2nr : np : ns 1
D1
Isolated v Non- Isolated Forward Converter
r ind
Iout
L =10A
Prof R T Kennedy
2006-2007
isolated converter advantages:
x multiple outputs possible
x isolation: no common input -output connection
'indirect converter'
x output voltage polarity choice: dependent upon winding polarity
x output voltage can now be varied dependent upon turns ratio
and duty cycle greater design flexibility in range of duty cycle..control
isolated converter disadvantages:
x extra
{
cost
{
size
weight
{
xlosses
xleakage inductance
{
winding resistance
{
core
{
{
overlap reduced output voltage
transient voltages
x core saturation (possible)
x core reset requirements
EET 423 POWER ELECTRONICS 2
Isolated v Non- Isolated Forward Converter
2
Prof R T Kennedy
2006-2007
