Research On Microgrid Cluster Operation Control Strategy Based On Consensus Algorithm

The dual-carbon target puts forward higher requirements for clean energy consumption and microgrid application.The microgrid has small capacity and low power supply reliability.The microgrid group with a certain scale and cluster operation can effectively improve the stability of microgrid operation.The traditional centralized control methods can not meet the needs of autonomous management and collaborative optimization because of the different architecture,operation goals and distributed distribution of each unit in the microgrid group.In this thesis,the following studies are carried out for the operation control of the microgrid group:Firstly,the structure of the optical storage microgrid group is established,and the working principle and operating curve of the internal microsource model are analyzed and verified by simulation.Based on distributed control,a multi-agent architecture for optical storage microgrid group is constructed,and a hierarchical and distributed control method for microgrid group is designed.At the bottom of each sub-microgrid system,a droop control strategy is used to achieve the automatic power distribution of each micro-source in the system.To solve the problem of voltage deviation in sag control,a collaborative voltage control based on error iteration is used in the subgrid layer to dynamically correct the voltage deviation.In order to solve the problem of inconsistent interest goals of each system in the microgrid group,an economic optimization strategy based on incremental cost consistency is adopted to balance the operating costs and benefits of each microgrid group to achieve the economic optimization of the microgrid group.In view of the phenomenon of power supply out of demand when large-scale micro-grid cluster is connected to the network,the weak grid problem is proposed and modeled.The system instability and voltage fluctuation in weak power network are analyzed.By constructing a new error iterative consistency tracking control strategy based on virtual leader,the source of voltage deviation is focused and the influence of weak power network is dispersed.The above control strategies are simulated in MATLAB/Simulink environment.The simulation results show that the bottom droop control can effectively distribute power,but there is a certain voltage deviation;Through the on-line correction of multi-agent voltage consistency control strategy,the convergence and control accuracy of micro source voltage are effectively improved;Combined with the equal micro increment rate criterion,the economic optimization strategy of microgrid group makes the incremental cost of sub microgrid the same on the premise of meeting the balance between load and generation,and realizes the lowest operation cost of the system.Finally,the weak power grid working condition and the corresponding control strategy are simulated.The results show that through the introduction of virtual leader,the convergence accuracy of micro sources is accelerated and the stability of system operation is effectively improved.