A high efficiency non-inverting multi device buck-boost DC-DC converter with reduced ripple current and wide bandwidth for fuel cell low voltage applications

Abstract

The voltage produced by the fuel cell (FC) device is unregulated and varies from 0.4 V to 0.8 V on full load to no-load respectively. When these devices are used in low voltage applications and output voltage lies between higher and lower values of input voltage range, it is required to connect a DCDC buck-boost converter to get a fixed output voltage. In this paper, a new noninverting multi device buck boost converter (MDBBC) is proposed, in which the multi device buck and boost converters are connected in cascade and operate individually either in buck or boost operating modes. The paper also includes the steady state analysis of MDDBC based on the state space averaging technique. A prototype model of proposed converter compatible with FCS-1000 Horizon FC model with rating of 270 W, 36 V is designed and developed. The proposed converter is experimentally validated with the results obtained from the prototype model, and results show the superiority of the converter with higher efficiency and lesser ripple current observed under steady state operation of the converter.

Keywords

• buck-boost converter
• multi device operation
• ripple current reduction
• buck-boost converters for portable applications