Investigation of Fiber Bragg Grating Temperature Sensor for Applications in Electric Power Systems

A reliable distributed temperature monitoring is very important for electric power systems because a power system failure will result in an enormous loss of life and property. Fiber Bragg grating (FBG) sensors, which have been studied intensively for last decade, can be very efficient tools for these applications because they are immune to EMI and can be highly multiplexed, which enables efficient quasi-distributed temperature sensing along tens of km range. We constructed a fiber-optic temperature sensor system with an array of 10 sensor gratings. The temperature-induced Bragg wavelength variations are accurately monitored by a scanned tunable wavelength filter. Differential measurement with temperature-stabilized reference gratings and a Gaussian curve-fitting algorithm has been used to enhance measurement accuracy, which obtained temperature resolution of ~0.6degC, and linearity error less than 0.4%