Research On Optimization Strategy For Microgrid Based On Finite-time Consensus Of Multi-agent

In recent years,due to the increasingly prominent environmental problems,the depletion of fossil energy and the increase of energy demand,distributed generation technology has developed rapidly due to its advantages such as low energy consumption,high efficiency and economy.As more and more distributed generation is incorporated into the large power grid,it will affect the safe and stable operation of the large power grid.To this end,it will be integrated into the large power grid in the form of microgrids.Due to the different working characteristics and cost characteristics of different types of power generation units in microgrids,it is necessary to study the economic optimization and control of microgrids.In order to ensure the reliability and expansibility of the system,this paper focuses on the distributed control of microgrid.Combining the consistency theory of multi-agent system(MAS)with the operation control of microgrid,a distributed hierarchical optimization strategy of microgrid based on the finite-time consistency algorithm is proposed,and the effectiveness of the proposed control strategy is verified by simulation examples.The main contents are as follows:(1)The mathematical model of the inverter is established,and the power transmission characteristics of droop control under different voltage levels are analyzed.In order to solve the optimization control problem of microgrid,the consistency theory of multi-agent is applied to the optimization control of microgrid.At the same time,in order to make the agent system convergence faster and control accuracy higher,the fast finite-time consistency algorithm is adopted.The stability of the control algorithm is analyzed using Lyapunov stability criterion.(2)Aiming at the problem of power distribution and voltage frequency control of microgrid,a power distribution and frequency voltage control strategy based on finite-time consensus algorithm was proposed.On the basis of droop control,this strategy uses the MAS consistency theory to estimate the total active and reactive power reserve capacity of the system.When the load changes,each power supply accurately allocates active and reactive power according to the proportion of its reserve capacity.Then,the output power of each power supply is assigned to this value by droop control principle.At the same time,introducing the frequency and voltage compensation amount,and applying the multi-agent consistency technology to achieve the system's frequency and voltage maintained at the rated value.(3)In order to ensure the optimal economic operation of the microgrid,and at the same time the frequency and voltage of the system can be stabilized at the rated value,a hierarchical optimization strategy for the microgrid based on the finite-time consistency algorithm is proposed.The strategy is improved on the basis of the power distribution,frequency and voltage control strategy of micro grid based on the finite time consistency algorithm.The first level control layer and the second level control layer are reserved,and introducing the concept of micro-increase rate in the third level control layer.According to the finite-time consistency theory and the "Equal Incremental Rate Rule",the optimal value of the power generation of each DG is solved,and the value is returned to the first level control layer.