RFID电缆中间接头无线无源湿度监测

Wireless passive humidity monitoring method of cable intermediate joint based on RFI

针对电缆中间接头受潮导致的运行故障问题,提出一种基于13.56 MHz RFID技术的无源湿度监测方法。该文利用HFSS建立传感器模型,调整天线匝距使天线达到理想状态,并对天线进行谐振匹配;然后研究传感器天线在水中的传输效果及存在金属屏蔽层时金属对天线性能的影响;最后将所设计的传感器放置于中间接头内部进行性能测试。结果表明:天线匝距为0.6 mm时传感器性能最佳;在天线外部增加47μH电容可实现13.56 MHz谐振匹配;传感器天线在水中的传输效果良好;加装金属屏蔽层可解决路径上金属对传感器信号传输的抑制作用;实际测量距离可达到8.2 cm、相对湿度测量误差最大为0.48%,最大波动幅度仅为0.3%,传感器长期处于高湿度环境仍能准确测量。该方法可实现电缆中间接头内部湿度的直接、快速及无源测量,对防止电缆受潮具有一定的参考意义。

Aiming at the problem of operation failure caused by moisture in the cable intermediate joint,a passive humidity monitoring method based on 13.56 MHz RFID technology is proposed.In this paper,the sensor model is established by HFSS,the antenna turns are adjusted to make the antenna reach the optimal state,the method of antenna resonance matching is proposed.Then,the transmission effect of the sensor antenna in water and the influence of metal on the antenna performance in the presence of metal shielding layer are studied.Finally,the designed sensor is placed inside the intermediate joint for performance test.The results show that the sensor has the best performance when the antenna turn distance is 0.6 mm;adding a 47μH capacitor outside the antenna can achieve 13.56 MHz resonance matching;the sensor antenna has a good transmission effect in water;adding a metal shielding layer can reduce the inhibitory effect of metal on the signal transmission path.The actual measurement distance can reach 8.2 cm,the maximum humidity measurement error is 0.48%,the maximum fluctuation range is only 0.3%.The sensor can still be accurately measured in the long-term high humidity environment.The method can realize the direct,rapid and passive measurement of the humidity inside the cable intermediate joint.The method is of great significance to prevent the cable from being damp.