Distributed Economic Dispatch Under Communication Constraints And Its Application In Microgrids

With the aggravation of the energy crisis,increasingly prominent of the environment issue,distributed generation technology becomes one of areas of research focus,which operates with higher efficiency of using resource,little pollution and so on.To mitigate the severe impact when distributed generation connects into the main grid,micro grid systems come into being since it can give full play to the advantages of distributed generation techniques.As the important means to realize security and stability of economic operation,micro grid economic dispatch is a significant part of micro grid technology.For micro grid systems,the most typical aim of economic dispatch is to minimize cost via allocation reasonably for output power of the generators,under the constraints of balance of system supply and demand.However,the economic dispatch in traditional centralized manner need to establish a complex communication network for global information,which has the shortcoming of high cost,demanding requirements of communication and poor stability.More and more attention to the economic dispatch has been paid based on distributed technology.Moreover,there are complexities of communication and limitation of communication and computing capability in practical systems,an economic dispatch strategy which can adapt to complicated communication environment and avoid wasting communication resources has inspired value and practical significance both in theory and application for the optimal configuration of micro grid systems.In this paper,we studied the distributed economic dispatch problem under the restriction of communication for micro grid systems,the main contents are as follows:(1)An economic dispatch model for micro grid under the restriction of communication is built.Consider in different complex communication conditions,the distributed scheduling strategy is formulated to minimize cost of micro grid system.(2)The time delay constrained economic dispatch problem for micro grid is considered and a distributed economic scheduling strategy with time delay is designed.Due to the scattered properties of distributed generation,consider the transmission delay between distributed generators based on long distance and the self delay required by generators for processing information,a distributed scheduling approach under the constraints of balance of system supply and demand is designed to minimize cost,realize economic dispatch.(3)An economic scheduling strategy for micro grid under the condition of time-varying topology is designed.Due to the risk of communication failure in actual transmission process,consider the communication topology between distributed generators is time-varying and the limitation of communication and computing capability,a distributed scheduling approach based on event-triggered framework is designed to eliminate unnecessary communication and reduce wasting energy,ensure the output power has an optimum value so as to realize the economic dispatch.