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Research On The Dispatch And Control Technique Of Multi-terminal DC Distribution Network Based On The Multi-time Scale

Posted on:2018-06-05Degree:MasterType:Thesis
Country:ChinaCandidate:L YangFull Text:PDF
GTID:2322330515457656Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
With the depletion of fossil energy sources and increasing environmental pollution,China is vigorously promoting the development and utilization of new energy technology.Along with the rapid development of power electronic technology,the traditional AC power distribution network is faced with the problem of lack of power supply corridor,low power quality and access of high density distributed renewable energy.The complexity of power flow control strategy makes the traditional AC power distribution network faces a great challenge.DC power distribution network has a greater advantage than the AC distribution network in terms of power supply capacity,reducing line loss,power quality and acceptance capacity of new energy.Because of its good compatibility with distributed new energy,DC power distribution network will become an important development direction of intelligent power distribution network in the future.In order to deal with the uncertainty of distributed power supply connected to DC power distribution network and solve the problem of inaccurate prediction accuracy which is decreased with the increase of time scale,a multi-time scale optimal scheduling strategy is proposed in this paper.The strategy is used to coordinate and optimize the distributed power supply,energy storage and the power of converter station in the DC distribution network to realize the maximum utilization of intermittent renewable energy sources.At the same time,the renewable energy and energy storage system are combined to form a controllable power source(CES),which can use the flexible charging and discharging behavior of energy storage to stabilize the power fluctuation.The role of different time scale scheduling is discussed in detail,and the scheduling process is given.Different optimal scheduling models are established at different time scales.Based on the long time scale,a multi-objective model considering the power grid dispatching cost and the new energy utilization rate is established,in which the storage capacity of grid connected is planned and the optimal configurable capacity of the energy storage is determined.On the short time scale,the short time scheduling strategy based on the voltage fluctuation is established to maintain the system voltage within the allowable range,which can ensure the stability of the system voltage.Using the specific example,the scheduling scheme under different conditions is simulated.The analysis and comparison of the results show that the proposed method and the model are effective.
Keywords/Search Tags:DC distribution network, optimal scheduling, controllable energy source, multi-time scale, capacity of energy storage
PDF Full Text Request
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