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Research Of Micro-grid Adaptive Control Based On The Hierarchical And Cooperation Of Multi-agent System

Posted on:2017-05-31Degree:MasterType:Thesis
Country:ChinaCandidate:C Y KongFull Text:PDF
GTID:2308330482480715Subject:Electronic and communication engineering
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As the problems of the energy supply and environmental pollution are becoming more and more serious, developing recycling and environment-friendly clean energy has become an inevitable choice for China to protect the security of energy supply, address climate change and improve the environmental quality. Micro-grid, represented by distributed generation system, can not only realize the diversification and intelligence of the renewable energy, but also be better able to meet the requirements of power quality and reliability. However, the introduction of the micro-grid into the power grid also changes the traditional distribution system model. Especially for the case with high micro-grid penetration, the distribution system is changing from a single power distributor into a power switching system, which is integrated with power concentration, energy storage, power transmission and power assigned. At the same time, the uncertainty and dispersion of distributed generation, the randomness of load change, the diversity of energy storage device, the flexibility of control strategy and other factors make the control methods of micro-grid more and more complex.The traditional centralized control normally uses a central control unit to unify the decision-making and scheduling, but there are a large number of distributed terminals in the micro-grid, which need to interact with the central control unit. Then the central control unit has to process a large number of data. It is very hard make decisions in time. Pure distributed control uses every distributed terminal in the micro-grid to decision-making and control independent according to the local information, and reduces the amount of data interaction with a central controller. But it’s easy to lead the control of power and load desynchronized, or event micro-grid splitting when serious. Therefore, the control requirements in meeting local electrical constraints of physical devices and the requirements to achieve the global coordination of the whole micro-gird, with totally different control goals, will inevitably lead to conflict. In order to achieve both the object management of local area and the global optimal energy allocation, this paper proposes a micro-grid distributed control system architecture based on the hierarchical and partitioned multi-agent system, which combines both the characteristics of the centralized control and the distributed control. Through the coordination between levels, the control system can achieve the distributed coordination control of regional autonomy of local control and global cooperation.Firstly, based on multi-agent technology and architecture, this paper adopts the method of centralized control and decentralized control, and divides the architecture of micro-grid control system into three layers: total control Agent layer, local control Agent layer and controlled device Agent layer. According to the division of different levels of Agent functions, the model and function module of each Agent are designed. Agent layer for the controlled devices has many energy coordinate objects, and the optimization goal of each object is different. Based on the goal of global optimal operation and local optimal operation of micro-grid, this paper builds a multi-objective optimization model and introduces a genetic algorithm to solve the multi-objective model. This algorithm can find the optimal operations of micro-grid system and keep the system in the optimized state during system changes.Secondly, according to the structure of the micro-grid, the model of micro-grid is built by Matlab/Simulink simulation software. At the same time, the micro-grid control system based on multi-agent is built by JADE which is an open source framework. In order to realize the coordination between different levels of micro-grid control system, this paper makes a detailed analysis of the scheduling algorithm of the local regional autonomy and the global cooperation, and introduces the TCP/IP to realize the communication between the micro-grid control system based on JADE and the micro-grid simulation model. The micro-grid control system can not only realize the simulation of micro-grid physical characteristics through the semi physical simulation platform, but also can achieve the optimal scheduling of micro-grid through the coordinated control algorithm.Finally, simulations on the coordination and scheduling process of Agents between different layers in three scenarios: grid-connected mode with load change, islanding mode with load change and grid-connected/islanding switch mode, are performed to verify the design of the adaptability and effectiveness of the control system. The simulation results show that the control system can realize the cooperation between different levels and ensure the stable operation of micro-grid under different operating modes.
Keywords/Search Tags:Multi-Agent, Hierarchical cooperation, Micro-grid control, Multi-Objective optimization, Genetic algorithm
PDF Full Text Request
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