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.