Comprehensive Modeling of Zonalized Autonomous Microgrid with Improved Voltage Profiles in the Renewable Generation Dominant Region

This paper presents results from the comprehensive modeling of autonomous microgrid with both conventional synchronous generator based generations and inverter based renewable generations. Zonalization or regionalization has been adopted in which the conventional generations are installed in one region while inverter based renewable generations are installed in another region. The former takes well-established droop control: \pmbf-P;\pmbV-Q to ensure proper power sharing among multiple conventional generators while constant frequency method is adopted to operate the latter. Back to back converter is used to join two regions, through which a planned power exchange is fulfilled. A modified method is adopted to improve voltage profiles in the renewable generation region through a combination of proportional controller, bounded integral controller and a bias. By doing so, bus voltage deviation from its rated value can be kept well within ±5%.