A grid connected PV micro-inverter with optimized battery storage utilization

Abstract

Photovoltaic (PV) installations on the residential scale have been increasing tremendously and projected to continue to do so. Battery energy storage at the residential level has also become critical due to the increased adoption of residential scale PV. This paper proposes a new micro-inverter topology with integrated energy storage for PV applications. The proposed topology has a structure similar to that of a flying capacitor multilevel inverter, with reduced switch count. This provides advantages such as design simplicity while being more cost effective than existing topologies. A unique control scheme is also proposed in this paper, which mitigates PV intermittencies while also optimizing battery utilization. The proposed topology and control technique are verified by simulation for a residential scale micro-inverter rated 230 W. The simulation results validate the micro-inverter operation and the control methodology.