Research On Hierarchical Control Of Microgrid Based On Multi Agent Consensus Algorithm

The increasingly serious environmental problems make human beings accelerate the development and utilization of clean energy,and distributed power generation,which mainly uses clean energy to generate electricity,plays an important role in the development of traditional power grids to smart grids.However,distributed power generation is usually geographically dispersed and influenced by weather and environment,so a large number of grid-connected will reduce the power quality and reliability of power supply,so some scholars propose microgrid.Microgrids can be operated in isolation or grid-connected,and their normal operation must meet the constraints of voltage,frequency and power in the system,so it is particularly important to implement effective control of microgrids.As the number of distributed power sources within the microgrid increases,the drawbacks of traditional centralized control become more and more serious,so this paper will investigate distributed control and study microgrid hierarchical control based on multi agent consensus algorithm.First,the primary control in the hierarchical control structure is studied.The inverter dq0 coordinate system model is established,the characteristics of three common control strategies for inverters and application scenarios are analyzed and compared,and droop control is selected as primary control.The low voltage level is verified by adding virtual impedance to make the total impedance of the line inductive to achieve proportional reactive power distribution and simulated in Matlab/Simulink.Second,the multi agent consensus algorithm is studied in order to improve the multi agent state consensus speed of distributed control microgrid.The graph theory basis used in the multi agent consensus theory is introduced,the first-order multi agent consensus algorithm and the finite-time consensus algorithm are analyzed,and the finite-time consensus algorithm is improved in order to improve the consensus speed and reduce the consensus time of the agent,and the stability of the algorithm is proved by constructing the Liapunov function.The m-file is written in Matlab for simulation and compared with classical consistency algorithm and other consistency algorithms to verify the effectiveness and fast convergence of the improved algorithm.Finally,the secondary control in hierarchical control is investigated to compensate the voltage deviation and frequency deviation of the microgrid.Although the virtual impedance droop control can realize the proportional distribution of reactive power,there are still voltage deviation and frequency deviation problems,for which the distributed proportional voltage control and distributed frequency control based on the improved finite-time consensus algorithm are proposed as the secondary voltage control and secondary frequency control,respectively.The agent achieves the compensation of voltage deviation and frequency deviation by collecting the output power of the respective distributed power supply and communicating with the neighboring agent.Simulations are built in Matlab/Simulink to verify the effectiveness of the secondary control as well as the overall control strategy;and compared with the secondary control constructed by other algorithms to verify the rapidity of the secondary control in this paper.There are 33 figures,5 tables and 80 references in this paper.