Development of a four quadrant DC-DC sepic converter

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.