A Hybrid Controller With Hierarchical Architecture for Microgrid to Share Power in an Islanded Mode

One challenge of utilizing inverter-based distributed energy resources in islanded microgrids is the proper power distribution between them. Improper power allocation causes resource overload and disturbs the balance of supply and demand, which can be eliminated using a droop controller. However, different operating points and loading conditions decrease the accuracy of this method. This paper aims to present a plan to improve the power distribution in islanded microgrids. To enhance the performance of droop control, the virtual impedance is exploited, giving the operator the ability to control the impedance between the inverter and the load effectively. The proposed method is evaluated and validated in the case of linear, nonlinear, and unbalanced loads.