变压器差动保护及励磁涌流识别研究

发布时间：2018-10-15 17:13

【摘要】：电力变压器是重要的电力设备,在实际应用中,要求电力变压器等电力设备长时间连续运转,这就不可避免的会诱导电力变压器等电力设备出现故障和事故。当其发生故障时,不仅会危及电网安全,而且严重时会造成重大经济财产损失。因此,为了监测变压器的内部运行状态,实时精确的辨别出变压器的潜伏性故障,有必要采取合理有效的保护性措施。变压器的纵差保护最需要迫切解决的难题是怎样精确的辨识出励磁涌流和内部短路故障电流,本文基于此作了相关的研究和分析,给出了一种新的辨识方法。另外,针对变压器的微机保护装置,本文以嵌入式技术为基础,给出了软硬件的保护设计。本文的大致内容如下:首先,介绍与研究了变压器纵差保护的背景和意义,对纵差保护中的重难点作了理论分析;其次,研究分析了变压器纵差保护的基本原理、励磁涌流的特点以及几种在实际中经常用到的辨识励磁涌流的判据,同时,研究分析了变压器微机纵差保护的判据和算法。接着,详细的介绍了相空间重构的理论,并以此为基础,重点利用3个几何不变量(关联维数、Kolmogorov熵和Lyapunov指数)来辨识变压器励磁涌流和内部短路故障电流。另外,通过MATLAB/SIMUL1NK软件搭建变压器的励磁涌流和内部短路故障电流的模型框架,针对变压器在不同条件下的运行状况实施模拟实验,并重点研究和分析了仿真出来的励磁涌流和内部短路故障电流的波形和数据之间的差别。最后,给出了基于TMS320F28335DSP的变压器继电保护装置的部分硬件模块的设计,并针对硬件设计部分给出了部分主要的软件设计流程图。
[Abstract]:Power transformer is an important power equipment. In practical application, power transformer and other power equipment are required to run continuously for a long time, which will inevitably lead to power transformer and other power equipment failures and accidents. When the fault occurs, it will not only endanger the security of power grid, but also cause serious economic property losses. Therefore, it is necessary to take reasonable and effective protective measures in order to monitor the internal operation state of transformers and identify the latent faults of transformers in real time and accurately. The most urgent problem of transformer differential protection is how to accurately identify the inrush current and internal short-circuit fault current. Based on this, a new identification method is proposed. In addition, based on embedded technology, the protection design of hardware and software is given for the microcomputer protection device of transformer. The main contents of this paper are as follows: firstly, the background and significance of transformer differential protection are introduced and studied, and the important and difficult points in transformer differential protection are theoretically analyzed. Secondly, the basic principle of transformer differential protection is studied and analyzed. The characteristics of inrush current and several criteria for identification of inrush current are often used in practice. At the same time, the criterion and algorithm of microcomputer differential protection for transformer are studied and analyzed. Then, the theory of phase space reconstruction is introduced in detail, and based on this theory, three geometric invariants (correlation dimension, Kolmogorov entropy and Lyapunov exponent) are used to identify inrush current and internal short-circuit fault current of transformer. In addition, the model frame of the inrush current and the internal short-circuit fault current of the transformer is built by MATLAB/SIMUL1NK software, and the simulation experiment is carried out according to the operation condition of the transformer under different conditions. The difference between the waveform and data of excitation inrush current and internal short-circuit fault current is studied and analyzed. Finally, the design of some hardware modules of transformer relay protection device based on TMS320F28335DSP is given, and some main software flow charts are given for the hardware design part.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM774

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