一种用于变压器局部放电在线监测的光纤声发射传感器实验研究

发布时间：2018-12-14 16:11

【摘要】：提出了一种光纤声发射传感器并构建传感系统实现变压器局部放电在线监测,利用传感光栅体积小,重量轻,灵敏度高和抗电磁干扰的特点,将传感器置于变压器内部实现局部放电声发射信号的测量。研究了传感光栅实现声发射应力波测量的机理,声发射信号引起传感光栅反射光谱发生漂移,导致特定频点处反射光强发生变化,通过反射光强的变化实现声发射信号的测量。构建声发射传感系统实验模型并提出了一种系统性能优化策略,使系统工作在传感光栅反射光谱上升或下降沿的半峰值频点处,从而保障传感系统具有良好的线性输出特性;研究传感系统工作点稳定技术,设计信号反馈回路自动跟踪反射光谱的漂移,保证系统稳定工作在传感光栅半峰值频点处,消除温度变化对传感系统测量精度的影响。将封装好的传感器用于变压器局部放电现场检测,结果表明,光纤光栅声发射传感器与压电传感器相比具有灵敏度高、动态范围宽等优点,可以实现变压器局部放电在线监测。
[Abstract]:A fiber optic acoustic emission sensor is proposed and a sensing system is constructed to realize the on-line monitoring of transformer partial discharge. The sensor grating is small in size, light in weight, high in sensitivity and anti-electromagnetic interference. The sensor is placed inside the transformer to measure the acoustic emission signal of partial discharge. The mechanism of acoustic emission stress wave measurement by sensing grating is studied. Acoustic emission signal results in the drift of reflection spectrum of sensing grating, which results in the change of reflected light intensity at a specific frequency point, and the measurement of acoustic emission signal through the change of reflected light intensity. The experimental model of acoustic emission sensing system is constructed and a system performance optimization strategy is proposed to make the system work at the half peak frequency point of the rising or falling edge of the sensing grating reflectance spectrum so as to ensure that the sensing system has good linear output characteristics. The working point stabilization technology of the sensor system is studied and the signal feedback loop is designed to automatically track the drift of the reflection spectrum to ensure that the system works stably at the half peak frequency of the sensor grating and to eliminate the influence of the temperature change on the measurement accuracy of the sensing system. The results show that the fiber Bragg grating acoustic emission sensor has the advantages of high sensitivity, wide dynamic range and so on, and can realize the on-line monitoring of transformer partial discharge.
【作者单位】：齐鲁工业大学信息学院;山东财经大学计算机信息与工程学院;
【基金】：中国博士后科学基金项目(20110491604) 山东省自然科学基金项目(ZR2012F014) 济南市高校院所自主创新计划项目(JN201402005)资助
【分类号】：TP212

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