Hierarchical Coordinate Control for DC Microgrid Clusters Based on Adaptive Droop Control

According to the different operating conditions of each sub-microgrid, different operation modes of microgrid are classified to guarantee stability operation of DC microgrid clusters when failure occurred in distribution network, and a coordinate control strategy for DC microgrid cluster is proposed based on adaptive droop control of energy storage. The grid connection or disconnection operation of multi-microgrid is controlled by voltage fluctuation of DC bus that is monitored real-time through microgrid central controller to maintain voltage stability of DC bus for each sub-microgrid. At the same time, the load power may be dynamically shared according to the state of charge (SOC) and maximum output power by using adaptive droop control to regulate parallel running energy storage units in sub-microgrid. Multi-microgrids simulation model is constructed on MATLAB/Simulink platform, and simulation results show that the proposed control strategy can improve the system stability and load power can be dynamically shared among energy storage units.