一种新型的高压电器温度在线测量系统

Novel temperature on-line measuring system for high voltage apparatus

基于螺旋形液晶填充光子晶体光纤的温度传感特性,提出一种新型的高压电器温度传感器系统。该传感器系统由宽带光源、螺旋形液晶、光子晶体光纤、光纤F-P腔(Fabry-Perot cavity)滤波器、信号处理放大电路等组成。将螺旋形液晶封装在光子晶体光纤的纤芯空气孔中,利用光子晶体光纤对温度和弯曲不敏感特性以及螺旋形液晶的螺距对温度变化非常敏感的特性,传感器的选择反射光波长依赖于温度的变化,采用光纤F-P腔滤波器解调出光波长的变化,利用反射波长与温度之间的关系,实现温度的测量。测量系统选用合适液晶,可以得到不同的温度测量范围,能对高压电器温度进行在线检测,测量精度可以达到±0.1℃以内,并具有本征安全、高精度、高电绝缘和抗电磁干扰、对应变和环境光变化不敏感以及与普通传输光纤兼容性好等优点。

A temperature sense system used in the temperature measurement of high voltage apparatus is presented based on the temperature sense characteristics of photonic crystal fiber （PCF） system consists of wideband optic source, helix liquid crystal, PCF, fiber Fab amplification circuit. The helix liquid crystal is packaged in the hollow core of with helix liquid crystal filling. The ry-Perot（F-P） cavity filter and signal the PCF; with the characteristics that the pitch of helix liquid crystal is very sensitive to temperature change and PCF is insensitive to temperature and bend, the selective reflection wavelength of the sensor is dependent on temperature change. The temperature may be measured in real-time based on the wavelength change demodulated by fiber F-P cavity filter and the relationship between selective reflection wavelength and temperature. Selecting different helix liquid crystals, different temperature measurement ranges can be obtained. Using this method, the temperature of high voltage apparatus can be measured, and the measurement error is less than ±0.1 ℃. The proposed temperature measurement system has the advantages of intrinsic safe, high precision, high electrical insulation, anti-electromagnetic interference; and is insensitive to strain and ambient light, and compatible with common transmission fibers.