A New Flying Capacitor-Based Buck–Boost Converter for Dual-Purpose Applications

A novel dual-purpose common ground dc–dc/dc–ac power converter is proposed in this article. It is based on the flying capacitor circuit along with a boost circuit, which in turn provides a wide range of input voltage regulation with the capability of stepping up or down the output voltage. The same components are used under both dc–dc and dc–ac modes, which reduces the redundancy of the used devices. Particular attention is dedicated to the working modes of the proposed solution. The special control system is implemented to provide acceptable current and voltage quality in off-grid and grid-connected modes. To underline the pros and cons of the proposed solution, a comprehensive comparison is performed. Finally, the performance of the proposed dual-purpose power converter is investigated through an experimental 3.5-kW/5-kW setup, for dc–ac and dc–dc operating modes, respectively. Main oscillograms along with efficiency analysis are presented and discussed in conclusions.