针对输电线路的雷击监测定位问题,提出一种基于导数极值局部最大值优化算法的雷击点定位方法.OPGW遭受雷击时,其内部通信光纤中传输光的偏振态由于Faraday效应产生突变.首先对偏振态信号进行降噪以及变换处理得到其幅度谱,然后采用导数极值局部最大值算法进行偏振态突变信号的起点位置寻优,通过记录偏振态突变信号到达偏振解调设备的时刻来实现雷击点定位.实验结果表明:导数极值局部最大值优化算法能够快速且准确的定位光偏振态突变信号波头,为输电线路雷击点的监测定位提供了一种新方法.

We propose and verify a fiber optic temperature sensor whose demodulation method is measuring the spectra contrast, which is quantified by the amplitude of the fast Fourier transform (FFT) of interference fringes within a certain small wavelength range. A section of polarization-maintaining fiber (PMF) is spliced in the sensing arm of the Mach-Zehnder interferometer (MZI). Due to the birefringence of the PMF, a visible envelope is formed in the interference fringes. Within a certain range of optical frequency (i.e. wavelength), the change of birefringence caused by external temperature will drive the envelope drift, and the amplitude of interference fringe after fast Fourier transform will also change correspondingly. By measuring the change of amplitude, the purpose of demodulating external temperature can be realized. Experimental results show high sensitivity better than 2.1 dB/degrees Cwith a high accuracy of 0.00048 degrees C, comparing with the envelope drift measuring results 1.62 nm/degrees C with resolution of 0.012 degrees C. The resolution of this scheme is increased by two orders of magnitude compared with measuring the envelope drift. Moreover, merits of our sensor in terms of immune to phase shift of reference arm and the power fluctuation of light source benefit our practical application for such as electric power system monitoring.

为实现输电线路单相断线故障的快速精准定位,缩短供电恢复时间,提出了一种基于OPGW光传感技术的光偏振态故障定位方法.根据法拉第磁光效应的原理,以光纤复合架空地线(OPGW)为传感器,通过自制设备捕获和分析输电线路相导线对OPGW产生的感应电流在单相断线瞬间的突变信号,实现对故障点的定位.在实验环境下进行模拟实验对其验证,结果表明:在给定的电流范围内,设备获取的信号强度与导线通电电流大小呈正相关,设备能有效捕捉线路断电瞬间的突变信号,实现故障点定位,定位结果误差在±250m内,满足工程设计的要求.