微电网故障暂态特性及集成保护

发布时间：2018-06-05 23:37

本文选题：微电网 + 故障暂态　；参考：《天津大学》2014年硕士论文

【摘要】：目前,各国纷纷开始研究高效的、可靠的分布式发电技术。微电网就是在分布式发电基础上形成的一种新型的供电方式,但是随着分布式电源的接入,改变了传统意义上的潮流特性和故障特性,又给大电网的运行与维护提出了许多新的挑战。本文主要研究了微电网的故障暂态特性,研究重点集中于逆变型分布式电源故障暂态特征。逆变型分布式电源通过电力电子装置接入电网,在其并网运行过程中,当电力系统出现扰动,逆变电源将由先前的稳定运行状态经过一系列调整回复到原有稳定状态或者过渡到新的稳定状态。先后两个稳定状态之间的调整过程称之为故障暂态过程。并网逆变电源在故障暂态过程中受控于自身控制器,为了研究控制策略对并网逆变型分布式电源故障暂态特征的影响,首先建立了能够反映逆变器控制策略的逆变型分布式电源的详细模型;在此基础上,详细分析了控制器控制参数对逆变型分布式电源暂态响应的影响;针对对称性故障和非对称性故障情况,对逆变型分布式电源的故障暂态特征进行深入的分析。针对分布式电源多点接入的配电系统而形成的微电网,提出了一种基于暂态极性保护原理的集成保护新方案。暂态极性比较保护是运用小波变换提取故障暂态高频信号的某一频段信息作为故障判断的依据,通过比较暂态高频信号的极性,迅速准确判断出故障位置。将暂态极性比较保护原理应用于微电网集成保护方案中,以母线作为载体构建集成保护单元,利用本地故障信息和相邻保护单元故障信息对母线各出线以及线路两端信号的极性进行比较,从而对母线故障和线路故障进行判断。与此同时集成网络保护单元提取多点信息,对整体区域暂态信号极性进行综合比较,实现对故障的快速定位与隔离,为本地保护提供后备保护。
[Abstract]:At present, many countries have begun to study efficient and reliable distributed generation technology. Microgrid is a new power supply method based on distributed generation, but with the access of distributed generation, it changes the traditional power flow characteristics and fault characteristics. It also puts forward many new challenges to the operation and maintenance of large power grid. In this paper, the fault transient characteristics of microgrid are studied, with emphasis on the transient characteristics of inverter distributed generation. The inverter distributed power supply is connected to the power network through power electronic devices. In the process of grid connection, when the power system is disturbed, The inverter will return to the old stable state or transition to a new stable state after a series of adjustments. The adjustment process between two stable states is called fault transient process. In order to study the influence of control strategy on the transient characteristics of grid-connected distributed power supply, the inverter power supply is controlled by its own controller during the transient process of fault. Firstly, a detailed model of inverter distributed power supply which can reflect inverter control strategy is established, and the influence of controller control parameters on transient response of inverter distributed power supply is analyzed in detail. In this paper, the fault transient characteristics of inverter distributed power generation are analyzed in detail in view of symmetric fault and asymmetric fault. A new integrated protection scheme based on the principle of transient polarity protection is proposed for the microgrid formed by the distribution system with multi-point access of distributed power supply. Transient polarity comparison protection is to use wavelet transform to extract some frequency information of transient high frequency signal of fault as the basis of fault judgment. By comparing the polarity of transient high frequency signal, the fault location can be determined quickly and accurately. The principle of transient polarity comparison protection is applied to the integrated protection scheme of microgrid, and the integrated protection unit is constructed with the bus as the carrier. Based on the local fault information and the fault information of adjacent protection units, the polarity of each outline and the two end signals of the bus is compared to judge the fault of the bus and the fault of the line. At the same time, the integrated network protection unit extracts the multi-point information, compares the polarity of the transient signal of the whole region, realizes the fast location and isolation of the fault, and provides backup protection for the local protection.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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