Two‐stage off‐grid system for catering household AC appliances with reduced switches

This study presents a solar photovoltaic (PV)‐battery‐integrated multi‐input converter (PBMIC) based two‐stage off‐grid system for catering household ac appliances in areas where the grid is not available. The proposed single‐stage PBMIC facilitates the control of both PV array and the battery along with adequate voltage boosting by employing only two controlled switches. This reduces cost for semiconductor devices along with associated accessories and also reduces a number of power converter stages required for the overall system. Owing to the adequate voltage boosting capability, the proposed system facilitates the use of low‐voltage levels for both PV and battery, thereby eliminating the problems associated with the series connection of multiple units of them. The topological configuration of the PBMIC under different modes of operation is analysed. Furthermore, a novel control scheme that allows the converter to operate in various modes necessary for an off‐grid system along with a seamless transition between these modes is also devised. A 400 W prototype of the complete off‐grid system formed by connecting a full‐bridge dc–ac inverter at the output of PBMIC is fabricated for conducting experimental studies. The validity of the complete system is substantiated by comprehensive simulation and experimental performance.