Energy Storage-less Single Phase Photovoltaic Supply System Operating in Grid and Autonomous Modes

This paper presents design and control of energy storage-less single phase photovoltaic supply system (SPVSS). The proposed SPVSS operates in both grid and autonomous modes. The topology of SPVSS consists of a step up converter (SUC), a full bridge single phase voltage source converter (VSC), single phase utility grid and local loads. The SPVSS is in grid mode as the utility supply is healthy. As and when, grid supply becomes abnormal, control smoothly transfer the SPVSS from grid to autonomous mode and vice versa. Whenever utility grid is in normal condition, SUC control is obtained using the optimum power control (OPC) and VSC is controlled through the current control strategy. Moreover as grid conditions become abnormal, SUC control changes from OPC to constant DC link voltage control, and VSC control shifts from current to voltage control respectively. An incremental conductance algorithm is used as OPC for SUC during grid connected mode. The viability of the proposed control strategy is confirmed by performing simulation on MATLAB 2019@ platform.