A Level-Increment Circuit for Multilevel Inverter Based on Cross-Connected Sources

Multilevel inverters (MLIs) are growing as a potential solution for DC to AC power conversion. This work describes the design and implementation of a single-phase newly developed multilevel inverter configuration that combines a cross connected sources (CCS) based MLI and a half-bridge inverter with considerable decrease in component count for a large number of output voltage levels. The level-increment circuit (LIC) is a type of half-bridge inverter that boosts the output voltage levels in the CCS-MLI topology by nearly twice. The aforesaid approach minimises the amount of power switching devices utilised compared to conventional topologies, resulting in higher output voltage levels by minimising the THD and dv/dt stress on the load. The proposed configuration can be designed to operate in both symmetrical and asymmetrical source patterns. Symmetrical arrangement allows for the formation of four more levels in each sequence with addition of each pair of switches to the basic module. The concept has been studied using MATLAB/Simulink and a laboratory prototype.