Modelling and simulation for INER AC microgrid control

A microgrid integrates renewable energy and other forms of distributed energy resources (DER) to serve its loads. The microgrid can increase the DER penetration and improve power quality and reliability through appropriate management. Under the normal operation, a microgrid is connected to the utility grid, and each DG provides a preset power to the network through active/reactive power control (PQ control), whereas the utility grid is responsible for supplying/absorbing any power discrepancy. When the microgrid is disconnected from the utility grid, at least one unit switches to droop control from PQ control in order to regulate the voltage and frequency in the microgrid and continue to supply power to local load. This paper adopts Matlab/Simulink to model and simulate an actual ac microgrid with proposed control strategies. Several operation conditions including grid connected mode, islanding mode and load variation are simulated. Results show that the proposed control strategies for the microgrid are effective.