Multilevel Converter Based on Series and Parallel Connections Using Floating Capacitor

This paper investigates a single-phase multilevel dc-ac converter composed of four series/parallel-connected H-bridges with floating capacitors. System model, pulse-width modulation (PWM) strategies, and a control strategy have been presented. An important variable is the control of the dc-links voltages in the floating capacitor. Thus, an individual balancing of dc-links voltages using auxiliary variables and redundant voltage vectors are shown in this work for different dc-link voltage ratios. Simulations and experimental results with several power levels show how the operating characteristics.