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Decentralized Coordinated Control Of Microgrid Based On Multi-agent System

Posted on:2016-08-21Degree:MasterType:Thesis
Country:ChinaCandidate:M F LvFull Text:PDF
GTID:2272330479450490Subject:Control Engineering
Abstract/Summary:PDF Full Text Request
The renewable energy power generation combining with utility grid is considered as an alternative solution for economical and environmental issues of conventional power systems. The concept of Microgrid is proposed for better renewable energy penetration into the utility grid. The Microgrid can be defined as low voltage distributed power networks comprising various distributed generators, storage and controllable loads. Several main advantages of the Microgrid can be given: improving renewable energy penetration level, better energy supply for remote areas, power balancing at local level with self-supplying possibility, and maintaining load supply during off-grid mode. Pivotal to the implementation of Microgrid are the control strategies and architectures that will operate the Microgrid systems. By aggregating loads and multiple distributed energy resources(DERs), renewable and traditional, the microgrid can be coordinated and controlled in a decentralized way instead of the traditional way.In this paper, a two-hierarchical decentralized coordinated control scheme based on the multi-agent system(MAS) is proposed to improve the security and the stability of the Microgrid. The coordinated switching control strategies are constructed in upper level agent to ensure the Microgrid security. The making process of the coordinated switching control strategies is regarded as searching the optimal switching operation mode by means of designing the constraint violation function and the color Petri-net(CPN), so that the operation mode of the Microgrid can be switched during larger power unbalance. The decentralized continuous control is designed by integrating the outer loop droop controller with the inner loop prescribed performance(PP) controller in the lower level unit agents to guarantee its unit system stability. Finally, the simulation results demonstrate the effectiveness of the decentralized coordination control based on MAS.In the Microgrid, DERs are controlled to deliver desired power to the system; meanwhile, to minimize circulating current is another important control objective in order to keep microgrid be operated stably. Then, the relationship between a circulating current and the output voltage of the DERs is analyzed. It is proved that if the output voltage of neighbour DERs can be kept as consensus, the circulating current can be suppressed effectively. In this paper, the coordinated consensus control strategy based on the MAS is adopted to make the output voltage of neighbour DERs keep as consensus. The simulation results demonstrate the effectiveness of the coordinated consensus control strategy based on the MAS.
Keywords/Search Tags:decentralized coordinated control, MAS, Microgrid, operation mode conversion, constraint violation function, inverter, circulating current, consensus
PDF Full Text Request
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