【作者】 郝金会；

【导师】 李绪友；

【作者基本信息】 哈尔滨工程大学 ， 精密仪器及机械， 2012， 博士

【摘要】 光纤电流互感器是一种测量电网中电流的传感器，它在电力行业中起着至关重要的作用。目前传统式的电子式电流互感器已经发展成熟，但它在小型化、人员安全等方面存在着困难。与传统的电子式电流互感器相比，光纤电流互感器采用光纤作为信号的传载介质及敏感介质，在实现光纤电流互感器小型化及安全性方面的优势明显。因此对光纤电流互感器的研究具有重要意义。本课题主要针对光纤电流互感器结构中的器件性能及环境因素的误差消除的若干问题进行了研究。论文的主要工作如下：1.对光纤电流互感器的理论模型进行了详细分析。根据琼斯矩阵理论建立各个光学器件的矩阵模型及传感系统的理论输出模型。针对光学器件的性能对系统输出误差进行了仿真分析，从理论上得到了反映误差规律的曲线。从仿真结果看来，要使得误差小于0.2%，分束器及波片的对接误差应控制在0.05°以内；波片的相位延迟角度应控制在0.3度以内。2.针对外界恶劣环境影响系统输出的问题，提出了相应的误差抑制方案。对于振动因素的影响，提出了增加补偿光纤线圈的方法来消除误差的方案。从理论上详细推导了此种方案在载体中有电流和无电流时两种情况时的振动消除效果的可行性并进行了实验测试。实验结果表明，此种方案能够极大的消除所敏感到的外界振动因素的影响；对扭转光纤传感线圈所受到的温度因素影响进行了理论分析，仿真结果表明，在温度变化时，扭转速率越大其相对温度变化的双折射值越大且扭转速率对温度的敏感性要高于弯曲半径对温度的敏感性。针对传感系统的温度漂移问题进行了温度实验，首次将小波神经网络应用到系统的输出误差补偿中，使得补偿后的误差在±0.5A以内。3.针对系统中光源的性能及光源强度噪声抑制方法进行了研究。根据光波色散理论，推导计算了光源波长稳定性对系统的影响。结果表明，随着传输光的光波长的增加介质的折射率是呈变小的趋势，而且在波长越长的范围内，其介质的折射率的变化率是逐渐变小的。因此，在选择光源时，选择长波长段的光源来降低光源波长稳定性对系统标度因数稳定性的影响。针对光源波长稳定性的控制问题，提出了递进式PID的控制算法并对光源泵浦进行了温度控制实验。实验结果表明在实验室环境下能够使得光源泵浦的温度控制在±0.05°以内，提高了光源泵浦的温度稳定性，进而使得光源输出具有很好的波长稳定性。针对光源强度噪声抑制问题，根据信号的相关性理论，提出了耦合器输出端增加偏振器的方法来提高信号的相关性，进而提高噪声抑制效果。4.对光纤环的四极对称缠绕方法进行了详细分析并实现了双环的四极对称缠绕；在闭环信号处理方式、时钟、PCB设计等方面，采取措施来优化电路系统，提高系统的稳定可靠性；光纤电流互感器的输出数据中包含有大量的噪声，把小波阈值去噪方法引入到光纤电流互感器的数据处理中，提出一种新型的具有更好的平滑性及连续性的软阈值函数。对小波阈值去噪效果进行了对比，采用Allan方差对滤波处理后的数据进行分析，并对滤波效果做出评价。更多还原

【Abstract】 Fiber optic current sensor (OCS) is a current sensor used in National Grid, which playsan important role in electric power system. At present, traditional electronic currenttransformer (CT) has reached a mature state, but it faces some difficulties such asminiaturization and safety. Compared with CT, Fiber optic current sensor, which use opticalfiber as the transmission and sensing medium has great predominance in miniaturization andsafety. Therefore, the research on OCS is of great significance. The performances of\opticaldevices in the system and environmental factors such as vibration and temperature have greatinfluence on the sensing signal. So a number of key issues in those were studied in thisdissertation, detailed as follows:1. The theoretical modal was analyzed in detail. Each optical device and sensing systemtheoretical modal were established according to Jones matrix theory. The output error basedon performance of devices was simulated and the curved which represent the effecting rulesare theoretically acquired. According to the simulation results, it was found that the jointingerror of splitter and the phase delay of the wave plate should be in0.05and0.3°, for the errorin0.2%.2. For the adverse environmental factor, the corresponding error suppressionscheme was put forward. For the influence of vibration, the additional fiber compensationcoil was proposed to suppress the error. The theoretical analysis and the correspondingexperimental tests were realized where there was current and no current in the wire. Theresults showed that the new scheme could suppress the extra vibration effects obviously. Thetheoretical analysis of the influence of temperature on the optical sensing coil was done. thesimulation result showed that the heat-reactivity of rotating rate was much bigger than theradius of the coil. For the output bias due to temperature changing, the wavelet neuralnetwork was induced into the output error compensation, and the error after compensationwas in±0.5A.3. The influence on the theoretical modal of performance of power source and thesuppression of resource intensity noise were researched. According to the theory of wavedispersion, the influence on the system of optical power source wavelength was analyzed.The result showed that the reflective index of the medium became smaller with the increaseof wavelength and the gradient becoming small too in the larger wavelength range. So, thebigger wavelength optical fiber source was the best choice for the stability of scale factor. Forthe stability of power wavelength, a new stepped-in PID control method was proposed, the new method could keep the temperature of the pump in the range of±0.05℃and make thepower source has good wavelength stability. For the suppression of resource intensity noise,in combination with relativity between signals, the new method of adding an extra polarizerafter the coupler was proposed. The new method could suppress the noise vastly.4. The winding method of fiber coil was analyzed in detail and the realization of windingmethod of two fiber coils with QAD was researched. The optimization methods in signalprocessing, PCB design and so on were researched. For the de-nosing of the output data ofoptical current sensor, the wavelet threshold de-noising method was induced into the outputdata processing and a new threshold function was proposed. Comparison to the ordinaryfunction was done and the de-noising results were analyzed using the method of Allanvariance.更多还原