A Single-Phase Single-Source 7-Level Inverter With Triple Voltage Boosting Gain

The cascaded H-bridge multilevel inverter (MLI) requires separate isolated dc sources to generate more than three voltage levels and to generate higher output voltage. This paper proposes a new MLI topology that requires only one dc source and is capable of generating seven voltage levels with triple voltage boosting gain. Three H-bridges are interconnected through two bidirectional voltage blocking switches to enable the integration of two switched-capacitors. Unlike the existing two-stage structure switched-capacitor-based MLI, the proposed MLI is a single-stage topology. It alleviates the voltage stress across switches such that low voltage stress of not more than the dc source voltage is ensured on all switches. In addition, capacitors voltage balancing is achieved automatically during operation. The operation of the proposed MLI is analyzed followed by verification through simulation and experimental test of a low power/voltage prototype.