New generalized topologies of asymmetric modular multilevel inverter based on six-switch H-bridge

摘要

In this paper, for high and low numbers of voltage levels, two new generalized multilevel converters are introduced, which comprise a six-switch H-bridge and several switched-source units. Switched-source units consist of bidirectional and unidirectional switches along with a dc voltage source. The two proposed topologies are compared with topologies based on the six-switch H-bridge, conventional H-bridge, and some new topologies regarding the number of switches, dc voltage sources, gate drivers, and per-unit voltage block on switches. The comparison results reveal the superiority of the proposed topology with low number of voltage level (LNL) and proposed topology with high number of voltage level (HNL) regarding the per-unit voltage block and number of elements, respectively. Thus, the proposed topologies lead to reduction cost and weight of system. Furthermore, for high number of levels, HNL topology is more appropriate than LNL topology and vice versa. The performances of the proposed 15-level LNL and 61-level topologies are simulated by MATLAB, and proposed 15-level LNL topology in producing all voltage levels is validated by experimental results.