The grid-connected and off-grid scheme of household storage is mainly for the micro-small energy system at the user end, which realizes the energy time shift, dynamic capacity increase, and emergency backup power when connected to the grid through connection with the power grid, and can provide power supply in combination with the photovoltaic power generation system to reduce the dependence on the power grid; In areas without electricity or when there is a power outage, the stored electric energy and the electric energy of photovoltaic power generation will be converted into standard alternating current through off-grid operation to supply household electrical equipment, so as to promote the development of household green electricity and smart energy.