Voltage control of a hybrid ac/dc microgrid in grid-connected operation mode

The stability of dc and ac bus voltage is of the most important issues in all microgrids including ac, dc or ac/dc hybrid microgrids. In this paper, a hybrid ac/dc microgrid is proposed to reduce processes of multiple reverse conversions in an ac or dc microgrid and to facilitate the connection of various renewable ac and dc sources and loads to power system. Also, all control schemes used among all converters are developed in order to improve the voltage stability of the dc grid. Results are achieved considering the uncertainty of the generators and loads existed in microgrid verifying the robustness of the controllers to restore and stabilize quickly the voltage of the dc grid.