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The Topology And Control Strategy Of DC Electric Energy Router

Posted on:2020-10-02Degree:MasterType:Thesis
Country:ChinaCandidate:J C XuFull Text:PDF
GTID:2392330599459445Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
In order to cope with energy crisis andenvironment pollution,vigorously development environmental protection resources technology is one of the effective solutions.Due to the intermittent and decentralized nature of environmental protection resources,the traditional power grid can not solve the problem of large-scale new energy access and consumption effectively,so the Energy Internet came into being.Energy Internet is the development of the future power grid.Electric energy routers have important research significance as the key equipment of the Energy Internet.At the same time,with the development of DC distribution grid and the increase of DC loads,DC distribution gird will be an indispensable part of the future power distribution system.It is promising to study on the DC electric energy router for DC applications.The main research contents of this paper are as follows:(1)A new topology based on the cascaded high-frequency transformer is proposed for the DC electric energy router applied to the medium and small power distribution scenarios.Compared with the structure including the common DC bus,it has the advantages of reducing cost and volume,improving efficiency and decreasing voltage level step by step,besides ensuring bidirectional flow of power and isolation of ports.In this paper,the working process,soft switching range and current characteristics of the DC electric energy router are analyzed in detail,and the feasibility is verified from the principle,which lays a foundation for subsequent analysis.(2)The operation mode and control strategy of the proposed DC electric energy router are studied.According to whether the DC electric energy router is connected to the grid,the operation mode is divided into two types: grid-connected and off-grid,and the grid-connected mode is subdivided into three working conditions according to the power flow of each port,and the control strategies in various operation modes are introduced in detail.The control strategy is divided into upper layer control and lower layer control,which respectively realize the functions of power conversion and energy management.By optimizing the output of the distributed power supply and the charge and discharge management of the energy storage device,the user-side economically optimal goal is achieved.(3)A method for designing the parameters of the main loop of DC electric energy router is proposed.The four-port is taken as an example to design the parameters.The simulation model is built in Matlab/Simulink to perform steady-state and dynamic simulation on various operating modes.Taking the changes of peak and valley electricity prices,distributed power output and energy storage state in one day into consideration,the energy management strategy of the proposed energy management strategy is simulated for the DC electric energy router of the house energy system.The simulation results verify the correctness and rationality of the proposed topology and control strategy.(4)A four-port prototype of port voltage 750V/380V220V/48 V and capacity 20 kW is designed,including the device structure,control system hardware and the host computer interface.Experiments were carried out under existing conditions,which verifying the content of this study in this paper.
Keywords/Search Tags:Energy Internet, DC Electric Energy Router, Energy Management, DC Power Distribution, Dual Active Bridge
PDF Full Text Request
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