Flying-capacitor-clamped five-level inverter based on switched-capacitor topology

This paper proposed a novel flying-capacitor-clamped five-level inverter based on bridge modular switched-capacitor topology. The inverter features the switched-capacitor circuit with step-up ability and the multilevel inverter circuit with flying-capacitor-clamped performance. With the composite structure, the number of components is cut down compared with the topology of conventional multilevel inverter, the voltage stress of most switches can be reduced, and part of switches can be operated under line voltage frequency. Hence, the potential of system efficiency and power density is released due to embed switched-capacitor circuit. Also, the cost is reduced obviously. More important, the optimized carrier-based phase disposition (PD) PWM method is employed as control strategy, the capacitor voltage can realize self-balance and quality of output waveform is improved significantly. After simulation, the prototype is built to validate the correctness and practicability of the analysis.