含有分布式电源的配电网故障检测与识别研究

发布时间：2019-03-05 07:19

【摘要】：随着全球能源危机的加重,分布式电源(Distributed Generator, DG)应运而生。分布式能源缓解了全球能源紧张的局势,然而随着分布式发电大量并入配电网,传统配电网具有的单一电源的辐射拓扑结构将会因此改变,其运行方式也会发生变化。这样就会造成配电网故障检测与识别的过程变得更加的复杂,现有的故障检测与识别方案就会受到影响,有的已经不再适用。因此,在大力建设智能配电网的背景下,有必要展开对含有DG的配电网故障检测与识别技术的相关研究。具体工作如下:(1)分析了接入DG后对配电网的影响,着重分析了配电网发生短路故障后对故障检测与识别的影响。针对故障检测,研究了基于小波奇异熵理论与模糊逻辑相结合的故障快速检测与识别方法,利用模糊逻辑输出,对配电网时常发生的几种故障类型做出了准确判断,有利于继电保护的实施及孤岛检测。(2)判断出故障类型后,针对发生率较高的单相接地故障,进行故障选线工作。首先,搭建了含有DG的故障仿真模型,其次对各线路零序电流进行了 S变换,对数据做了预处理,提取了故障特征,找到特征频段及判定故障线路时刻,最后,在特征频段内进行各线路的暂态能量计算。针对暂态能量法在含有DG的配电网中选择故障线路的应用的局限性,提出了暂态能量比值自适应的选线方法。实验结果表明利用小波奇异熵理论与模糊逻辑的方法在含有DG的配电网中能够快速地检测出故障并能够对故障进行准确分类;利用暂态能量比值自适应的选线算法能够适应含有DG的配电网,能准确地识别出故障线路,有良好的适应性并且提高了保护裕度。
[Abstract]:With the aggravation of global energy crisis, distributed power supply (Distributed Generator, DG) emerges as the times require. Distributed energy reduces the global energy tension. However, with a large number of distributed power generation incorporated into the distribution network, the radiation topology of the single power supply in the traditional distribution network will be changed, and its operation mode will also be changed. This will cause the process of fault detection and identification of distribution network to become more complex, and the existing fault detection and identification schemes will be affected, some of which are no longer applicable. Therefore, under the background of building intelligent distribution network, it is necessary to study the fault detection and identification technology of distribution network with DG. The specific work is as follows: (1) the influence of DG access on distribution network is analyzed, and the influence of short circuit fault on fault detection and identification is emphatically analyzed. For fault detection, a fast fault detection and recognition method based on wavelet singular entropy theory and fuzzy logic is studied. By using fuzzy logic output, several kinds of fault types frequently occurring in distribution network are accurately judged. It is beneficial to the implementation of relay protection and island detection. (2) after judging the fault type, the fault line selection is carried out for the single-phase grounding fault with high incidence. Firstly, the fault simulation model with DG is built. Secondly, the zero sequence current of each line is transformed into S transform, the data is preprocessed, the fault feature is extracted, the characteristic frequency band is found and the fault line time is determined. The transient energy of each line is calculated in the characteristic frequency band. In view of the limitation of transient energy method in fault line selection in distribution network with DG, an adaptive line selection method based on transient energy ratio is proposed. The experimental results show that the wavelet singular entropy theory and fuzzy logic can quickly detect the faults and classify the faults accurately in the distribution network with DG. The adaptive line selection algorithm based on transient energy ratio can adapt to the distribution network with DG, identify the fault line accurately, have good adaptability and improve the protection margin.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM711

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