Two-Layer Cooperative Control for Multiple Converter-Network Clusters

Cooperative control are mainly employed for multi-converter networks due to the distributed nature of renewable resources and communication network limitations. By dividing all converters within each converter-network (CN) cluster into the leader-converters and follower-converters according to their physical cluster topology structure, the leader and follower control layers are respectively formulated. Then a two-layer cooperative strategy is developed, under which the weighted average voltage of all converters can be regulated to their rated references, meanwhile, the accurate current sharing can be simultaneously realized not only within each CN cluster but also among multiple CN clusters. Compared with previous work, the proposed control strategy has the advantages of accurate current sharing, short time consumption and faster convergence. All controllers are fully distributed and can be applied in all sparse two-layer cyber networks, and control time constant condition is derived to ensure the system stability. Different cases in MATLAB/SimPowerSystems are investigated to verify the effectiveness of the results.