变压器绕组变形的在线监测研究

发布时间：2018-01-08 00:06

本文关键词：变压器绕组变形的在线监测研究　出处：《北京交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：电力变压器是电力系统中的重要组成部分,一旦发生改障将会造成重大的经济损失甚至是严重后果。绕组变形是影响变压器安全运行的重要因素,进行故障诊断可提高其运行可靠性。论文工作研究了变压器绕组的传递函数特性,并应用于在线监测,为变压器绕组变形的在线监测研究打下了理论基础。建立了变压器绕组的仿真模型,综合考虑了变压器绕组的损耗和各线饼间的互感。以某台连续式单绕组变压器为算例,介绍了变压器绕组等值电路模型中的元件参数的计算方法和等效电路模型的建立过程。研究了仿真分析绕组变形的结构参数法,分析不同形式和程度的变形引起的绕组结构和尺寸变化,根据变形情况重新计算等效电路中的参数。基于对变压器绕组变形分析的传递函数法基本原理,利用不同时间的绕组传递函数曲线的相关系数ρxy和差值的均方根值Exy,作为诊断绕组变形的判据。仿真分析了变压器绕组发生单饼和多饼不同类型、不同程度变形时对传递函数的影响。论证了可将变形前后的ρxy和Ex,值作为特征量对绕组变形程度进行判断,并给出了相应的判断绕组轻微、中等和严重变形的区分阈值。研究了根据传递函数极点数目把传递函数曲线分为低频、中频、高频进行频域分段分析的方法,分别在全频域和各分段计算相应的ρx,和Exy,值,综合两者对绕组状态进行判断。成功的将仿真得到的结果应用到实际中,仿真模型及其分析通过了试验验证,为绕组变形的在线监测提供了理论基础和算法依据。在仿真和实验研究的基础上,得到了变压器绕组变形在线监测的方法,通过在线比较绕组传递函数曲线的方法来实现对绕组变形的在线监测。对实际变压器进行在线实验研究,验证了方法的可行性,为变压器绕组变形的在线监测提供了理论支持。利用LabVIEW软件平台,设计并实施了基于虚拟仪器的变压器绕组变形在线监测系统,具备在不改变一次设备接线方式的情况下实时不间断监测的能力,实现预警和报警。在线监测系统同时监测变压器工作电流,如果发生短路或过负荷现象,系统可以自动加强监测密度,具有一定的智能性。
[Abstract]:Power transformer is an important part of power system. Once the failure occurs, it will cause great economic losses and even serious consequences. Winding deformation is an important factor affecting the safe operation of transformers. Fault diagnosis can improve the reliability of transformer windings. The transfer function characteristics of transformer windings are studied and applied to on-line monitoring, which lays a theoretical foundation for on-line monitoring of transformer winding deformation. The simulation model of transformer windings is established, and the losses of transformer windings and mutual inductance between wires are considered synthetically. A continuous single-winding transformer is taken as an example. This paper introduces the calculation method of element parameters in the equivalent circuit model of transformer windings and the process of establishing equivalent circuit model, and studies the structural parameter method for simulation analysis of winding deformation. The structure and size changes of windings caused by different forms and degrees of deformation are analyzed, and the parameters of equivalent circuits are recalculated according to the deformation. Based on the basic principle of transfer function method for analysis of transformer winding deformation, the correlation coefficient 蟻 XY of different time winding transfer function curve and the root mean square value of difference value Exy are used. As a criterion for diagnosing winding deformation. The effect on transfer function of transformer windings with different types and degrees of deformation is analyzed by simulation. It is proved that 蟻 XY and Ex before and after deformation can be changed. The value is used as the characteristic value to judge the degree of winding deformation, and the corresponding threshold to judge the slight, moderate and severe deformation of the winding is given. The transfer function curve is divided into low frequency according to the number of poles of the transfer function. In the method of if and HF, the corresponding 蟻 x, and exy, values are calculated in the full frequency domain and in each segment, respectively. The simulation results are successfully applied to practice, and the simulation model and its analysis are verified by experiments. It provides theoretical basis and algorithm basis for on-line monitoring of winding deformation. On the basis of simulation and experimental research, the on-line monitoring method of transformer winding deformation is obtained. On-line monitoring of winding deformation is realized by on-line comparison of winding transfer function curves, and the feasibility of the method is verified by on-line experimental research on actual transformer. It provides theoretical support for on-line monitoring of transformer winding deformation. An on-line transformer winding deformation monitoring system based on virtual instrument is designed and implemented based on LabVIEW software platform. It has the ability of real-time and uninterrupted monitoring without changing the connection mode of primary equipment to realize early warning and alarm. The on-line monitoring system monitors transformer working current simultaneously if short circuit or overload occurs. The system can automatically strengthen the monitoring density, and has certain intelligence.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM41

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