Abstract:
In this thesis, a new topology of four quadrant DC-DC sepic converter has been
developed to provide four quadrant operation of a high frequency dc-dc converter
having one supply source and proper control of the converter.
The investigation started with modifying single quadrant dc-dc SEPIC converter
circuit for two quadrant operation. This required a dc-dc SEPIC converter with two
switches. Two quadrant dc-dc SEPIC converter has been investigated with variable
duty cycle operation for verifying the buck-boost gain characteristics of the voltage
and also the circuit has been investigated with input/output dc sources for two
quadrant operation as the duty cycle is varied from near zero to near one.
One quadrant SEPIC dc-dc converter is similar to a buck-boost converter, but it has
advantages of having non-inverted output and continuous input current. Connecting a
switch across the diode of the one quadrant SEPIC dc-dc converter in parallel has
made the converter operate in two quadrants. Proper differential connection of two 2Q
SEPIC dc-dc converter has resulted in a four quadrant dc-dc converter with buckboost
gain characteristics having positive output voltage.
The result is a single source topology switched by conventional ON/OFF duty cycle
control as used in other high power chopper circuits. The combined topology has been
analyzed and studied by spice simulation. Conversion efficiency and gain data has
been taken from simulation result and the performance has been analyzed and studied
by Tecplot10 Software.
