【作者】 王永；

【导师】 赵书涛； 何平；

【作者基本信息】 华北电力大学 ， 电工理论与新技术， 2011， 硕士

【摘要】 变压器局部放电模式识别的研究对于及时发现潜在故障,防止电力系统重大事故发生具有重要意义。目前变压器局部放电模式识别主要有电脉冲法和气相色谱法。由于现场强烈的电磁干扰和复杂的变压器内部结构,电脉冲法的识别效果并不理想。气相色谱法虽然不受电磁干扰影响,可帮助分析大致放电类型,但不能说明放电形态和位置,且存在严重的滞后现象,不利于及时发现潜在的故障。变压器局部放电产生的超声波信号受电磁干扰小,但频带较窄、波形复杂且易受变压器内部结构影响。在深入分析电脉冲信号和超声信号各自特点基础上,本文提出基于电声综合分析的局部放电模式识别方法,并建立了软硬件实验分析系统。首先,根据局部放电产生原理与特点,建立了变压器五种放电模型,搭建了局部放电实验系统。主要包括测量子系统、耦合子系统、传输子系统以及实验系统的原理图和接线图。其次,针对实验系统常见空间干扰、电源干扰和地干扰以及接地电阻影响,分别给出对应的硬件抑制措施以及软件消干扰方法。软件方法采用基于小波变换的消除干扰算法,并与傅里叶消干扰方法进行了对比分析。然后,分析了变压器局部放电电气定位法的特点与不足,研究了各种电声定位法和声声定位法;提取电脉冲信号时域特征和超声波信号统计特征,构建特征向量,实现了典型的放电模式识别。最后,开发了变压器局部放电分析系统,包括数据采集与显示、小波变换与傅里叶变换消干扰、超声定位和放电模式识别等软件模块。更多还原

【Abstract】 Partial Discharge Pattern Recognition for the timely detection of potential failures, to prevent the occurrence of major accidents power system is important. PD pattern recognition in the current transformers are electrical pulse method and gas chromatography. Because the field a strong electromagnetic interference and the complex internal structure of the transformer, electric pulse method of identifying the effect is not ideal. Gas chromatography from electromagnetic interference, high recognition accuracy, but there is a serious lag is not conducive to timely detection of potential failures.Transformer partial discharge by the ultrasonic signal generated by electromagnetic interference is small, but the band is narrow, the waveform is complex and susceptible to influence the internal structure of the transformer. In-depth analysis of electrical pulse signals and ultrasound signals based on their own characteristics, this paper presents a comprehensive analysis based on electro-acoustic partial discharge pattern recognition method, and the establishment of the Experimental Analysis of hardware and software systems.First, according to the principle and characteristics of partial discharges, the establishment of five discharge of transformer model, set up a partial discharge test system. Including measurement subsystem, coupled subsystem, transport subsystem and the experimental system schematic and wiring diagram.Second, common space for the experimental system interference, power disturbances and interfere with and affect the grounding resistance, the corresponding hardware are given disincentives and software destructive interference method. Software method using wavelet-based algorithm to eliminate interference and destructive interference with the Fourier method were compared.Then, the analysis of transformer partial discharge location method of electrical characteristics and disadvantages of various positioning methods and the sound of acoustic location method; extract the electrical pulse signal characteristics and the ultrasonic signal in time domain statistical features, build feature vectors, to achieve a typical Discharge pattern recognition.Finally, the development of the transformer partial discharge analysis system, including data acquisition and display, wavelet transform and Fourier transform destructive interference, ultrasound and discharge pattern recognition and other software modules.更多还原