Feasibility study of the application of optical voltage and current sensors and an arrayed waveguide grating for aero-electrical systems

In this paper we present, for the first time, the hybrid fiber-optic voltage and current sensors interrogated using an arrayed waveguide grating (AWG) device. Due to the excellent dynamic capabilities of an AWG-based interrogator and its improved robustness, the proposed system would be suitable for voltage and current monitoring within an aircraft electrical system. The voltage sensor comprises a multilayer piezoelectric stack, acting as a voltage-to-strain transducer, and a fiber Bragg grating (FBG) used to convert voltage induced strain changes within the stack into wavelength shifts. These wavelength shifts are then analyzed by an AWG. To measure current, the same sensor type is used to monitor a specially designed ferrite-core current transformer. Alternatively, a magnetostrictive transducer is employed instead of piezoelectric stack. It is shown that the system is capable of measuring variable frequency of voltage and current waveforms, typical of those anticipated in the next generation aero-electric power systems. It is also demonstrated that the system can be used for voltage and current harmonic analysis and power quality measurement in such networks.