Management and Control for Smart Microgrid Based on Hybrid Control Theory

The increased penetration of distributed generations introduces considerable complexity in the network operation, as well reliability if the distributed generations are effectively controlled and managed. Hence, the issues of management and control for smart microgrids become more significant. With respect to a large power system, a microgrid shows more conspicuous interactive hybrid dynamic behaviors. In this study, a novel hybrid model is first founded to clearly explain the hybrid interactive behaviors of microgrids. On the basis of the model, a two-level hierarchical hybrid control is proposed based on the hybrid system control theory in terms of interactive adjustment between the continuous controller at the lower level and discrete management at the upper level. The upper-level discrete management strategies are responsible for guaranteeing stability and security of the overall microgrid while constraining it to meet the load demand during significant disturbances, as well as minimizing the operating cost and reducing the emission during normal situations. The lower-level local continuous controllers are responsible for regulating the dynamic performance of each controlled unit to reach a satisfactory level. The effectiveness of the proposed hybrid control is demonstrated through simulation example.