In this brief presents, first a basic structure of 15-level single-phase inverter is presented. The proposed topology works asymmetrically and is capable of producing positive and negative voltage levels at the output. Then, to produce more output voltage levels, the basic structure is expanded and a cascaded multi-level structure is obtained. The new structure is analyzed and compared with several structures in terms of the number of power electronic components used. The result of the comparison shows that the proposed structure uses less power electronic components and is more cost-effective compared to others. Considering the state of the switches and depends on the application, it is possible to use the different kinds of intelligent control methods. Finally, to prove the results, the 15-level inverters is simulated in PSCAD/EMTDC software program. تفاصيل المقالة

Todays, the multilevel inverters are becoming popular for medium/high power applications. In the meantime, the cascaded multilevel inverters use less power electronic elements. In this paper, first, a new basic unit is proposed for cascaded multilevel inverters. The basic unit is capable of producing four positive output voltage levels. Then, to achieve a higher number of voltage levels at the output side, several basic units are used in series connection. Because the proposed basic unit cannot produce zero and negative levels, so to solve this problem, one H-bridge is used to obtain zero and negative output voltage levels. The proposed topology is analyzed and different factors such as rating voltage, number of levels, required DC voltages sources, power electronics components, and gate driver circuits are calculated. Moreover, the proposed inverter is compared with several other topologies. As a result, the proposed topology needs to less number of power electronic elements, DC voltage sources and gate driver circuits. To prove the correct operation of the proposed topology, the simulation results of a nine-level inverter in PSCAD/EMTDC software program are used. تفاصيل المقالة