瓷绝缘子振动声学检测方法研究及应用

发布时间：2018-03-10 19:47

本文选题：瓷绝缘子　切入点：振动声学　出处：《华北电力大学》2017年硕士论文　论文类型：学位论文

【摘要】：瓷绝缘子是电网系统的重要组成设备,起着支撑导线和绝缘作用。由于电瓷产品是一种混成的材质,主要由分布在玻璃态基体里的石英粒子组成,由于基体与石英粒子线膨胀系数不同,导致瓷件内部容易出现微裂纹缺陷。而由于陶瓷材料是典型的脆性材料,裂纹非常容易扩展从而导致严重的后果。常规检测瓷绝缘子的方法如超声波检测等方法存在对微裂纹缺陷检测效果差,干扰因素多、或不能在线检测等不足,难以满足对瓷绝缘子进行有效检测及诊断的需求。针对以上情况,本文提出了一套完整的瓷绝缘子振动声学在线检测方法,并将该方法通过大量的对比试验及现场检测应用,最终证明了所提方法的有效性及可靠性。本文首先对振动声学检测进行了理论上的详细分析,通过振动有限元分析得出了瓷绝缘子在受激时的振动模态及动态响应,掌握其在有无缺陷条件下的振动规律变化情况,为进一步试验提供指引方向。其次,分别采用阶跃信号(锤击)和连续白噪声(专用白噪声信号发生器)对完好的及有缺陷的瓷绝缘子分别进行激励,得出缺陷的存在会对不同激励下的振动频率造成不同的影响,验证了仿真的正确与可靠性,且这种变化即为瓷绝缘子振动声学检测方法的主要依据。之后,论文介绍了为检测瓷绝缘子缺陷所建立的一套完整的声学检测系统,包括其硬件组成及软件开发。最后,将所建检测系统通过试验的方法得出其检测评价准则,并将其用于现场瓷绝缘子的检测,且获得了较好的检测结果。
[Abstract]:Porcelain insulators are important components of the power grid system and play the role of supporting wires and insulation. Because porcelain products are a mixed material, they are mainly composed of quartz particles distributed in the glass matrix. Due to the difference of linear expansion coefficient between the matrix and quartz particles, micro-crack defects occur easily in the porcelain, but the ceramic material is a typical brittle material. The crack is very easy to expand and lead to serious consequences. The conventional methods of detecting porcelain insulators, such as ultrasonic detection, have some disadvantages, such as poor detection effect of micro-crack defects, many interference factors, or failure to detect them on line. It is difficult to meet the requirement of effective detection and diagnosis of porcelain insulators. In view of the above situation, a complete method of vibration acoustic on-line detection of porcelain insulators is proposed in this paper, and the method is applied through a large number of comparative tests and field tests. Finally, the validity and reliability of the proposed method are proved. Firstly, the vibration acoustic detection is analyzed in detail in theory, and the vibration mode and dynamic response of the porcelain insulator are obtained by vibration finite element analysis. To grasp the changes of vibration law in the presence or absence of defects, to provide a guiding direction for further tests. Secondly, Step signal (hammering) and continuous white noise (special white noise signal generator) are used to excite the intact and defective porcelain insulators respectively. It is concluded that the existence of defects will have different effects on the vibration frequency under different excitations. The correctness and reliability of the simulation are verified, and this change is the main basis of the vibration acoustic detection method of porcelain insulator. After that, the paper introduces a set of complete acoustical detection system for detecting the defect of porcelain insulator. Finally, the detection and evaluation criteria of the system are obtained by means of experiments, and it is applied to the detection of porcelain insulators in the field, and good results are obtained.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM216

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