Research On Multi-microgrid Optimal Scheduling Based On VSG Technology

With the popularization of microgrid applications,the number of microgrids appearing in local areas is increasing exponentially.However,the operation of a single microgrid sometimes cannot meet the power demand of the load.Therefore,this article focuses on the interconnection operation of multiple microgrids.The tie line connects multiple micro-grids,which can effectively realize the circulation and interaction of energy,and also realize the mutual support of energy between micro-grids.This paper takes the multi-agent system as the theoretical control framework,and proposes an optimal scheduling strategy for multi-microgrid energy management,which can reduce the output fluctuation of the multi-microgrid system and improve the economy of the entire power system.Here is a brief summary of the work carried out:First of all,considering the potential threats caused by the uncertainty of frequency fluctuations to the multi-microgrid system,it was decided to improve the control strategy of the inverter in the microgrid,and use advanced virtual synchronous machine control technology to replace the traditional droop control strategy.The introduction of the moment of inertia and damping characteristics of the traditional synchronous generators enables the micro-source to ensure that the frequency fluctuations will not be too severe when disturbed by external factors,providing a safe and stable environment for the off-grid operation of the multi-microgrid system.Secondly,analyze the operating principle and working characteristics of common distributed power sources,and establish a mathematical model about its cost.In addition,summarize the relevant background and principle characteristics of the multiagent system,apply it to the control structure of the multi-microgrid,and analyze the functional tasks of each unit agent in the multi-microgrid system in detail,laying a good theory for the progress of the subject basis.Then,the solution process and operating characteristics of the two-level programming principle are analyzed,and on this basis,a two-level optimal scheduling model for the multi-microgrid system is established,and at the same time,different optimal scheduling goals for the upper and lower levels of the system are established.According to the different optimization goals of the upper and lower layers,the corresponding scheduling strategy is formulated to optimize the system scheduling.At the same time,in order to promote the healthy and upward development of the multimicro-network trading market,this paper has formulated a flexible micro-network group standard trading mechanism.Then,for the solution of the two-layer optimization model,an improved quantum artificial bee colony algorithm is proposed,and the relevant algorithm flow is designed to search for the optimal solution of the model.Finally,through specific calculation examples to verify the optimal scheduling model and strategy,it is found that the two-tier optimal scheduling model can not only reduce the overall output fluctuation of the system,but also improve the overall economy of the system.The results show that the proposed two-tier scheduling optimization model and related scheduling strategies can be effectively used in multimicrogrid systems.