Hierarchical control techniques applied in micro-grid

At present, the centralized control and decentralised control are adopted in micro-grid. In order to send command information from master controller to slave controller, centralized control must have a high bandwidth communication channel, which is not suitable to execute the peer-to-peer and plug-play control. And when a new micro-source is interconnected to the micro-grid, the master controller will have to adjust all the micro-source once more. Decentralised control is operated using only local information, but, because without reference from the global pattern, the global optimal performance can´t be guaranteed as firmly as with global controllers. In this paper, a novel hierarchical control for micro-grid is proposed, this control method still have a certain degree of decentralisation but also keep a degree of centralization through a higher level control layer that controls lower level units. The hierarchical control is mainly consisted of three control levels: primary control, secondary control and tertiary control. Experimental results are provided to show the feasibility of the hierarchical control method.