Modeling and Analysis of Separated Capacitor Series Resonant DAB Based DC-AC Converter for Photovoltaic Micro-Inverter

This article proposes a quasi-single-stage topology for photovoltaic micro-inverters based on the Separated Capacitor Series Resonant Dual Active Bridge (SCSR-DAB). The fundamental operating principles of the topology are introduced, followed by a detailed analysis of the circuit's behavior in various operating modes. On this basis, the equivalent structure and mathematical model of the SCSR-DAB are established to simplify the requirements for converter control and analysis. Compared to traditional micro-inverter topologies, this topology inherits the advantage of a wide soft-switching range of conventional DAB, while integrating resonant technology, which results in higher efficiency and better control performance. Finally, the proposed converter and its mathematical model are validated through experimental results.