Control Technique for Inverter Based Micro Grid

A Microgrid (MG) is essentially a low-voltage network comprising local distributed energy sources and local loads. Typically, MGs are small-scale power supply systems with total installed capacities ranging from a few hundred kilowatts to a few megawatts. The primary objective of microgrids is to supply power to remote areas or villages utilizing locally available resources where no grid connection exists. Additionally, microgrids can be designed to provide uninterrupted, high-quality power to sensitive loads within a specific area. Microgrids can operate in two modes: grid-connected mode and islanded mode, each requiring distinct control strategies. This project focuses primarily on the islanded mode operation. In the existing method, the virtual output impedance technique is employed. However, this approach can amplify the magnitude of harmonic currents due to the derivative of the output current, leading to power supply interruptions and unsatisfactory power sharing among inverters. To address these issues, a new control technique is proposed, integrating the Second Order Generalized Integrator (SOGI) with virtual output impedance. This method effectively enhances the impedance and limits circulating (harmonic) currents in the inverter. The primary objective of this project is to minimize harmonic currents in the inverter and ensure proper power sharing among inverters during islanded mode operation using the proposed control technique. The proposed method is implemented and validated through simulation in the MATLAB/SIMULINK environment.