Isolated Single Primary Winding Multiple-Input Converters

Abstract

Multiple-input converters (MICs) have attracted more attentions because of its simpler structure and less devices. In the traditional isolated MICs, each input source always has a primary winding, sharing a secondary winding. When the number of the input sources increases, the number of the primary windings increases, resulting in complicated structure of the transformer, poor coupling, and large leakage inductors. This paper first introduces the concept of pulsating source cells (PSCs), including pulsating voltage source cells and pulsating current source cells, and the connection rules for the PSCs. Then, series- or parallel-connected PSCs are used to replace the input dc voltage source or input dc current source in the isolated single-input converter, and a family of isolated single primary winding (SPW) MICs is proposed. Compared to the traditional isolated MICs, the transformer has only one primary winding, leading to a simplified structure and ease for manufacturing. Furthermore, the voltage stress of the power switches is reduced. The control method of the proposed isolated SPW MICs is proposed. Finally, a flyback SPW double-input converter is analyzed as an example. The operation principle and control method are discussed and a prototype is built to demonstrate the feasibility of this topology.