Font Size: a A A

Study On Islanding Protection And Control For DG Based On Wide Area Information

Posted on:2016-03-14Degree:MasterType:Thesis
Country:ChinaCandidate:X ZhangFull Text:PDF
GTID:2272330461487566Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
With the high development of economy, more and more people have been paying attention to the energy crisis and environment deterioration and expect the new energy to come true. So, the distributed generation is brought into being, and countries of the world focus on it for its being practicable and environment-friendly. With the development over the past ten years, the technology of distributed generation has been mature, especially the wind power generation and photovoltaic power generation being into the stage of large scale power generation. But, it still faces technological challenges, especially the seamless handover technology between the connected mode and islanded mode and the control technology, in addition to the low voltage ride through (LVRT) of distributed generation (DG).The paper proposes a novel islanding protection strategy considering the islanding detection of DG, LVRT and the application of recloser, and according to two approaches of DG connected to distribution, it presents three strategies of DG reconnected to distribution. The core of the paper compensates for the vacancy in current references and affords a theoretical support for the development of related technology.Firstly, the paper summarizes the research results of current islanding detection technology. According to active detection, passive islanding detection and islanding detection based on communication, it presents the methods of three detections respectively and analyzes the detection progress of methods in brief phrases, summarizes the theoretical principle of every method and advantages and disadvantages of three islanding detections separately.Then, according to the current islanding detection, the paper proposes a novel islanding protection based on wide area information. Based on the traditional islanding detection, the novel scheme uses the location information of circuit breaker to confirm the island or not. About the core, it introduces the current communications compactly, namely optical fiber communication and feeder automation master station communication. Considering the feature of two communications, the scheme determines the communication style; and based on the real running of DG, it presents the communication schematic diagram of the DG connected feeder and bus; lastly, according to the two typical methods of DG connected to distribution, it presents the reactions of islanding protection when the DG is in islanded mode caused by three faults separately. Not only does the paper present the criterions of novel islanding detection, but also it proposes the control logic of LVRT, flow chart of islanding protection and analyzes the coordination feasibility between recloser and LVRT in running time. The paper builds two kinds of schematic diagram of DG connected to distribution in terms of non-planed islanded mode caused by three faults to simulate and test the feasibility of criterions of islanding protection and illustrates the differences between inverter power and synchronous power in term of maintaining the voltage level.Lastly, based on the related references about DG reconnected to distribution, it summarizes the current strategies of DG reconnected to distribution. According to the two methods of DG connected to distribution, the paper summarizes three kinds of reconnected modes, namely taking microgrid as carrier, connecting to distribution by point of common coupling (PCC); connecting to distribution by feeder, the unexpected islanded mode caused by special faults needs related circuit breaker to reclose to connect to distribution; connecting to distribution by bus, DG as independent power to run or be isolated is reconnected to distribution by PCC. Furthermore, the paper presents the feature and technical requirements of three kinds of reconnected mode.
Keywords/Search Tags:DG, wide area information, islanding protection, recloser, reconnected to distribution
PDF Full Text Request
Related items