Research On Coordinated Control Method Of Microgrid Based On Event-triggered Consensus

In recent years,the problems of environmental pollution and resource shortage have become increasingly serious.In order to achieve the "dual carbon" goal and solve the problem of efficient utilization of renewable energy,microgrid technology has become one of the current research hotspots.The traditional time-triggered periodic communication method requires high network bandwidth,so it is of great significance to study the event-triggered microgrid coordinated control strategy.The thesis mainly conducts the following research on microgrid voltage/frequency coordinated control,economic scheduling,and other issues based on the Cyber-Physical System(CPS)control architecture:(1)Based the networked control theory and hierarchical control theory,the hierarchical control architecture of the microgrid CPS is constructed for the AC microgrid system.The CPS is composed of physical layer,information layer and service layer.The physical layer and information layer solve the problem of voltage and frequency stability control of microgrid.The physical layer,information layer and service layer combine to complete the economic dispatching of microgrid.The layered architecture is built to provide a basis for subsequent research.(2)Aiming at the problems of communication delay,high sampling rate,and many controller updates in the networked microgrid system,a distributed coordinated control method based on event-triggered consensus is proposed by combining the event-triggered method with the consensus algorithm.The distributed power generation is regarded as the intelligent node in the distributed sparse network,and the consensus algorithm is applied to design the state observer,and the event trigger condition is designed according to the state information of the intelligent nodes.When the event is triggered,the observer transmits the actual state value to the controller and the information to the neighbor controller.This control method requires the distributed controller to communicate when the event is triggered,which can effectively reduce the number of controller updates and reduce the system’s requirements for network bandwidth.The simulation results show that compared with distributed consensus,this method can realize voltage/frequency control of microgrid system,and the controller has less communication times,and the system has better robustness under communication delay.(3)Because the convergence time of the control system in the event-triggered consensus control method cannot be guaranteed,the system’s anti-interference ability is poor,and the power in the island microgrid system is difficult to be accurately distributed,etc.,the finitetime consensus method and the event-triggered method are combined to propose a finite-time event-triggered consensus coordinated control strategy for the island microgrid.The finitetime consensus algorithm is applied to design the secondary controller.The information in the controller is updated when the event is triggered,effectively reducing the number of controller updates,and realizing the accurate distribution of voltage and frequency to the rated value in a finite time.The simulation results in Matlab/Simulink show that the proposed strategy has good dynamic performance.(4)Aiming at the slow convergence speed of the control system and the large number of samples in the microgrid distributed economic dispatch strategy,a microgrid economic dispatch strategy based on finite-time event-triggered consensus is proposed.The proposed strategy aims to minimize the total power generation cost of DGs in a microgrid system.Under the constraints of meeting the DG power generation capacity constraints and power supply and demand balance,the incremental cost rate of each DG can converge to a consistent value within a limited time,and the optimal power output value of each DG at the lowest cost can be obtained,while reducing the number of samples.