Generalized Design Approach of a Family of Grid-Connected Converters Based on Active Virtual Ground Technique for Single-Phase AC Microgrid Applications

Abstract

The paper presents the state-of-the-art technique Active Virtual Ground (AVG) in the design of single-phase grid-connected converters which fully covers the entire applications on AC microgrids. Based on the three main components of the microgrid, the presented topologies belonging to the AVG series are divided into three different groups, which are associated with power consumers, renewable energy, and energy storage systems. The whole series of the single-phase converters are also based on the latest AVG technique. Therefore, in each application, a corresponding single-stage AVG converter can be found, which has high efficiency, low leakage current, and continuous grid current. The topology advantages and the working principle of the AVG converter family are demonstrated through the circuit evaluation and are experimentally verified in a set of 650 to 800 W prototypes which shows a good agreement on between both of the experimental results and theoretical finding.