基于非相干OFDR的分布式传感电力电缆温度在线监测和载流量计算

Temperature Monitoring and Ampacity Calculation for Power Cable Based on Incoherent OFDR Distributed Fiber Sensors

根据电力电缆温度监测的需求,本文设计了基于非相干OFDR的分布式光纤温度传感器,并给出了在恒温和温度有突变情况下的仿真结果。由于拉曼后向散射信号微弱,噪声干扰严重,本文采用小波分析方法对测试信号去噪处理,提高系统的信噪比。为计算电缆导体的载流量,本文基于传热学基本原理,采用有限单元自动划分法建立电缆稳态温度场模型。结合电缆物性参数及外界环境因素,分析电缆各层及其周围敷设区域的稳态温度场分布情况,并提出了一种基于二分法的电缆导体温度计算方法,可实现电缆导体载流量的快速准确计算。

In order to further meet the demand of powercable temperature monitoring,we design the distributed fiber temperature sensor based on incoherent OFDR,and give the simulation temperature results in the case of constant temperature and sudden temperature changes,respectively. As the Raman backscattering signal is weak and the noise is serious, the wavelet analysis method is used to denoise which it improves the signal-to-noise ratio of the system. In order to calculate the ampacity of cable conductors,the steady-state temperature field model is established by finite element method based on the basic principle of heat transfer. Combined with the eable physical parameters and external environmental factors,we analysis the steady-state temperature field distribution of each layer and its surrounding area. Subsequently, a method of calculating the cable conductor temperature is proposed by dichotomy, which can make the cable conductor ampacity calculation more efficient and accurate.