Decentralized Control Strategy for Hybrid Microgrid Based on Coordinate Coefficient

This work attempts to establish a control strategy for power management of hybrid microgrid consisting of different voltages of AC and DC subgrids. These subgrids are interfaced through power electronics converter to the common bus which is formed by an energy storage system i.e., battery. The converter interfacing this battery and common bus are bidirectional in nature and controlled by Pdc–Vdc2. Bidirectional AC–DC converter (BDAC) for AC subgrid and Bidirectional DC-DC converter (BDDC) for DC subgrid are controlled by droop-controlled techniques. The interaction among these subgrids in a coordinated manner requires communication which leads to the reduced reliability of the system. Hence a decentralized control strategy based on coordinate coefficient is studied in this work to interact among the subgrids in case of change in load. The generating capacity of the DERs connected to the subgrids is considered for the calculation of coordinate coefficient. The system is studied in Simulink for the load changes in AC subgrid with three stages of operations i.e., when the rated load is applied, when the load is increased without increasing power of DERs and when the generating capacity of the DER is increased. A comparative study was also done with coordinate control and without coordinate control.