A Nine-Switch Nine-Level Voltage Inverter New Topology with Optimal Modulation Technique

Multilevel converters are becoming increasingly used in multitude of industrial applications due to the many advantages that they offer. However, the multilevel converter consists of numerous drives and power switches, which lead to a considerable and increased cost and size of the device. To mitigate these issues, this article firstly reviews and compare the main topologies of conventional and modular multilevel converters (MMC) and the different multilevel modulation techniques. A comparative performance is investigated in order to develop a novel topology of a multilevel bidirectional inverter with minimum of semiconductor components or power switches and without any diode clamped or flying capacitor. Only nine switches are used to generate nine voltage levels in this new topology. We perform also a novel modulation technique based on fundamental frequency modulation and multi-carrier-based sinusoidal pulse-width modulation schemes. This MSPWM technique is implementing in order to reduce switching losses in power semiconductors. The performance study of the multilevel inverter and the designed modulation strategy are made by simulations in Matlab/Simulink environment.