Parallel three-level converter with less ripple current and balance output current

This paper presents a new three-level converter to achieve the advantages of zero-voltage switching of power switches, low voltage and current stresses of rectifier diodes, less transformer secondary winding turns, and low output current ripple. Two three-level circuit cells shared same active switches to reduce current stresses of passive components on the primary and secondary sides and to increase output power. In each circuit cell, two filter inductors and four rectifier diodes are used on secondary side to lessen output ripple current and transformer secondary winding turns. Half-bridge circuit shared the lagging-leg switches of three-level converter are adopted to achieve wide zero-voltage switching range. Two transformers are used in the half-bridge circuit to balance output currents of two three-level circuit cells. The circuit performance of the proposed converter are verified by laboratory experiments.