Hybrid Switched-Capacitor Multi-Level Inverter for Renewable Energy Systems

Abstract

A new hybrid switched-capacitor multilevel inverter is proposed. The proposed inverter consists of a combination of the switched-capacitor units connected in series and the T-type bidirectional switches connected to an H-bridge. This inverter has the reduced number of components and generates the boosted multilevel output voltage in a single-stage without any bulky magnetic devices, which can make the size and cost of a power inverter substantially reduced. It can also generate the high voltage multilevel output waveforms only by using the low voltage DC-sources and the low-voltage devices. In addition, the guaranteed capacitor voltage balancing can be achieved by the proposed modulation method with the T-type switches. Experimental results with a nine-level inverter system are presented to demonstrate the proposed topology and modulation method.