A Five-Level Flying-DC-Source Multilevel Inverter with Self-Regulated Voltages and Boosting Capability

In this paper, a novel single-phase five-level inverter is proposed. It is composed of eight switches and one flying-dc-source. Compared with the conventional active-neutral-point-clamped five-level inverter, the proposed structure has the same number of active devices and it does not require any sensor or balancing circuits to control the split dc-link capacitors. Thereby, the proposed converter reduces the cost and the complexity of the control system. Additionally, the proposed inverter has the capability of boosting the input voltage by a factor of two, which means it allows a reduction of 50 % in the DC-link voltage requirement and it does not require an intermediate DC-boosting stage for applications such as, photovoltaic panels and full-cells systems, characterized by a low and unregulated input voltage. Experimental results have been performed in order to validate the theoretical analysis of the proposed system.