Design and Analysis of a Novel Transformer-less Bidirectional DC-DC Converter with Wide Voltage Conversion Range for Energy Storage Systems

In this paper, a novel transformer-less bidirectional DC-DC topology with wide voltage conversion range is proposed for energy storage systems. The novel topology is constituted of one inductor, two capacitors, two active power switches, and two synchronous rectifiers. It achieves wider conversion range and lower power electronic devices voltage stress than the conventional buck-boost topology without using extreme duty ratio. The control strategy is easy for the simple structure of the new topology. The steady-state theoretical analysis and operating principles of the topology are explained in detail. Besides, the voltage stress and current stresses of switches are analyzed. Finally, in order to verify the feasibility of the topology, a 12-48V/48-12V model was built in MATLAB and pave the way for subsequent experimental verification.