An Off-Grid Photovoltaic Inverter Topology with a DC-Side Resistor

Off-grid systems for household are proposed to solve problems that population in remote areas lacks electricity. In an off-grid home, electrical appliances can result in poor power quality issues working on the conventional inverter structure. In this paper, proposing an improved photovoltaic inverter structure, in which adds a resistor at DC side. The resistor can stabilize DC-side voltage and supply enough power for inductive loads. In this system, the converter and inverter are controlled by a PI controller separately. The effectiveness of the proposed structure is verified by Matlab/Simulink software based on simulation results of the conventional structure and improved structure. By comparing their DC-side voltage, load voltage waveforms, and the THD values corresponding to an inductive load, the simulation results show that the proposed structure can achieve higher power quality.