Wavelength-division-multiplexed in-fibre Bragg grating Fabry-Perot sensor system for quasi-distributed current measurement

A novel technique for quasi-distributed grid current measurement using a wavelength-multiplexed in-fibre Bragg grating (FBG) Fabry-Perot sensor system interrogated by low-coherence interferometry (LCI) is demonstrated. This sensor system combines the advantages of both FBGs and fibre-optic LCI. A current range of over 700 A with a resolution of 0.3 A/root Hz has been achieved. The system cross-talk was measured to be less than -70dB. As this system is insensitive to both vibration acting on the fibre-leads and temperature change, ii could be suited for simultaneous measurement of three phase currents in power-distribution industry