Hierarchical control architecture of co-located hybrid power plants

Utility-scale co-located hybrid power plants (HPPs) have received global attention due to enhanced controllability and efficient utilization of electrical infrastructure. While control of mono-technology plants has been extensively studied over the past decades, the control of co-located HPP including sub-plants of multiple technologies is yet to be addressed. This paper fills such gap by proposing a novel hierarchical control architecture for co-located HPPs. Said architecture contains four control levels: asset control level, plant control level, HPP control level and energy management system (EMS). The objective of the EMS is to generate optimal bidding strategies for market participation, while the HPP control level is to execute real-time dispatch plans achieving the expected targets regarding active power and energy. Attention is paid to the interactions across different control levels of the hierarchy, particularly between EMS and HPP control level, and HPP control level with plant control level. Novel strategies for control coordination are presented to ensure all the control levels work together without counteracting against each other. Frequency control and fault ride-through are employed as examples to demonstrate such coordination.