Self-Balanced Twenty Five Level Switched Capacitor Multilevel Inverter with Reduced Switch Count and Voltage Boosting Capability

Multilevel inverters (MLI) are gaining wider popularity owing to their increasing power handling capability and improving power quality output. With an inclining trend towards renewable energy utilization, they find a vital application in wind and solar power generation systems. This article proposes a new multilevel dc-ac inverter. The proposed MLI produces a twenty five level output and offers an inherent capacitor self-balancing capability. The inherent self-balancing eliminates the requirement of auxiliary sensor circuit or capacitors voltage balancing algorithms. Dual asymmetric voltage sources and switched capacitors along with their proper charging/discharging pattern are utilized for the generation of output levels. A voltage gain of 2 and a total standing voltage (TSV) of 10 is achieved though the proposed inverter. In order to realize the merit of the proposed MLI over recently developed topologies, a comparative analysis in terms of system components such as numbers of power electronic switches, gate driver circuits, diodes, and capacitors as well as system parameters such as voltage gain, TSV and power loss is presented. The proposed MLI is developed in the laboratory and is controlled through the digital signal processor TMS320F28379D using nearest level control technique. The experimental results are acquired for different loads and under varying modulation index to validate the feasibility of the proposed inverter.