Closed Loop Control of Transformerless Interleaved High Step-Down Conversion Ratio DC-DC Converter

Abstract

This paper proposes closed loop control of transformerless interleaved high step-down conversion ratio dc-dc converter.The proposed converter utilizes two input capacitors which are series charged by the input voltage and parallel discharged by a new two phase interleaved buck converter for providing much higher conversion ratio without adopting an extreme short duty cycle.The proposed converter features uniform current sharing characteristic of the interleaved phases without adding extra circuitry.It also reduces the voltage stress of both switches and diodes.This will allow one to choose MOSFETs with low voltage rating to reduce both conduction and switching losses.Closed loop PI controller is used to control the error and finally achieves the desired output voltage.The operation principles, steady state analysis and comparison with other existing topologies are presented.Simulation results are presented to demonstrate the effectiveness of the converter.