A new technique for parallel connection of commutation cells: analysis, design, and experimentation

A new technique useful for the parallel connection of commutation cells is introduced in this paper. It consists of using small inductances in order to ensure dynamic and static sharing of the commutated current among the different switches. The operating principle, theoretical analysis and design procedure are presented. Experimental results, obtained from a 400-W buck power converter prototype using two commutation cells, have been used to validate the theoretical analysis and demonstrate the effectiveness of the proposed technique. Several experiments have been also accomplished to clear up the advantages of this new technique in comparison to the conventional one. Results from a three-cell buck DC-DC power converter delivering 4.5 kW are also presented, revealing a balanced current sharing among cells and an excellent dynamic behavior, as foreseen in the theoretical analysis