基于一次电光效应的非接触式过电压监测传感器研究

发布时间：2018-11-14 20:18

【摘要】：高压电网中过电压的测量对于研究过电压的行为特征和绝缘配合设计具有重要的意义。随着先进光学技术的飞速发展，将抗干扰能力强的光电传感技术运用到电网过电压监测已成为可能。因此，本文将光电转换技术和耦合电容技术结合起来，研究非接触式过电压传感器，配合实现过电压的无源非接触测量。本文所研制的电网过电压传感器的主要原理为：采用耦合电容分压的方式，将过电压的幅值降低，再通过特殊晶体的一次电光效应，将低幅值的过电压信号转换为随之变化的光信号，并通过光纤将信号传输到后台处理，最终经过反算获得原始被测过电压信号。传感器主要由两大部分组成：非接触分压单元和光电传感单元。根据实际测量的需求，本文根据耦合电容法，设计了非接触分压单元的结构和参数，并通过仿真计算和试验结果对非接触分压单元的分压比进行验证和确定。本文最终选定LiNbO3晶体作为材料研究和设计光电传感单元，并对其进行精密封装，验证了其感应低压信号的准确度和灵敏度。最后，将两个部分结合起来组成传感器整体，并对其进行了冲击电压试验，将原始被测电压与反算的电压进行对比，表明传感器具有较高的精度和频率响应速度，能够满足工程上过电压测量的要求。论文取得的主要成果有： ①通过耦合电容法实现了以非接触的方式将高幅值过电压信号转化为低电压小信号，并将其作为一次电光效应的输入源信号。试验结果表明：该方法的冲击电压响应时间误差在3%以内，测量峰值的误差为2%以内。 ②通过一次电光效应制作光电传感单元实现了电信号到光信号的转换，试验结果表明：光电传感单元能精确测量幅值在[-20,20V]之间的任意波形电压，频率能达到MHz级别。 ③将耦合电容法和一次电光效应法结合起来，实现了过电压的非接触无源传感，，并进行了误差分析提出了改进措施。本文提出的非接触式光电过电压传感器最终能够实现对过电压的幅值和波形准确测量，具有无源，抗干扰能力强，且与电力系统一次设备电气隔离的优点，是该领域研究的重大技术突破。其测量结果将有效指导过电压的防护设计工作，保障电力系统安全稳定运行。
[Abstract]:The measurement of overvoltage in high voltage power system is of great significance to study the behavior characteristics of overvoltage and design of insulation coordination. With the rapid development of advanced optical technology, it is possible to apply the anti-jamming photoelectric sensing technology to the power grid overvoltage monitoring. Therefore, in this paper, the photoelectric conversion technology and the coupled capacitance technology are combined to study the non-contact overvoltage sensor and realize the passive non-contact measurement of the over-voltage. The main principle of the overvoltage sensor developed in this paper is that the amplitude of the overvoltage is reduced by the way of coupling capacitance, and then the primary electro-optic effect of the special crystal is adopted. The low-amplitude overvoltage signal is converted into the varying optical signal, and the signal is transmitted to the background processing through optical fiber, and the original overvoltage signal is obtained by inverse calculation. The sensor is mainly composed of two parts: non-contact partial voltage unit and photoelectric sensor unit. According to the requirement of the actual measurement, the structure and parameters of the non-contact partial voltage unit are designed according to the coupling capacitance method, and the partial pressure ratio of the non-contact partial voltage unit is verified and determined by the simulation calculation and test results. In this paper, the LiNbO3 crystal is selected as the material to study and design the photoelectric sensor unit, and the precision packaging is carried out to verify the accuracy and sensitivity of the inductive low voltage signal. Finally, the two parts are combined to form the whole sensor, and the impulse voltage test is carried out. The comparison between the original measured voltage and the back calculated voltage shows that the sensor has high precision and frequency response speed. Able to meet the requirements of overvoltage measurement in engineering. The main achievements of this paper are as follows: 1 the high amplitude overvoltage signal is transformed into low voltage small signal by coupling capacitance method, and it is used as the input signal of primary electro-optic effect. The experimental results show that the response time error of impulse voltage is less than 3% and the error of measuring peak value is less than 2%. (2) the conversion of electrical signal to optical signal is realized by making a photoelectric sensor unit by a single electro-optic effect. The experimental results show that the photoelectric sensor unit can accurately measure the arbitrary waveform voltage between [-20 ~ (20) V] and the frequency can reach the MHz level. (3) the coupling capacitance method and the primary electro-optic effect method are combined to realize the non-contact passive sensing of overvoltage, and the improvement measures are put forward through error analysis. The non-contact photoelectric overvoltage sensor proposed in this paper can measure the amplitude and waveform of the overvoltage accurately, which has the advantages of passive, strong anti-interference ability and electrical isolation from the primary equipment of power system. It is a great technical breakthrough in this field. The measurement results will effectively guide the protection design of overvoltage and ensure the safe and stable operation of power system.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM933.2

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