Design of High Efficiency Step-Down Converter for Electro Chemical Energy Conversion

Abstract

Recently the research interest in power electronics interface for fuel cell has increased. And the static characteristics of fuel cells show more than a 30% difference in the output voltage between no-load to full-load conditions. Thus inevitable decrease, which is caused by internal losses, reduces the utilization of fuel cells at low loads. Fuel cell is a electrochemical energy conversion device which directly produces electricity. Thus, a step-down converter is required to transfer  from a high input  voltage  to an efficient and constant low level voltage. Maintaining high efficiency under a wide loading range is important in fuel cell.The aim of this work is to design a stepdown converter with DCM operation under light load not only can  reach high  efficiency  in heavy-load, but also has great improvement in light-load efficiency. The output accuracy and the output ripples obtained are better than other converters under light-load and as good as a normal PWM converter under heavy-load. Circuit simplicity and high reliability are the major advantages of the proposed converter. Using this technique, the utilization factor and efficiency of the fuel cell is increased. And this paper, focuses on the simulation and implementation of DC-DC converter fed fuel cell. Validation of the proposed model is verified through simulation.

Keywords: Fuel cell, Stepdown converter, PWM