| Abstract |
This paper proposes a multilevel asymmetrical inverter topology based on the H-bridge topology witha bi-directional switch connected between the switches of one inverter leg and the middle point of theinput DC voltages, resulting in new cell here referred as CHB-as cell. The cascaded association of twoCHB-as cell with appropriate input voltage sources can provide inverter output voltage with up to 25levels. This paper proposes the use of a HB inverter to connect one dc source and a multiwinding transformer as a ca-ca stage to produce the asymmetrical necessary voltages to supply the two CHB-ascells. This proposal increases the converter efficiency and reduces the total number of components,maintaining low total harmonic distortion in output voltage when compared with conventional multilevel converter to produce the same number of levels at the output voltage. Simulations results for a 1 kW, 220 V with load RL are presented and validate the proposed converter with ca-ca stage using optimum switching states. This topology does not require the use of any additional diode bridge. |
