Simultaneous flux and temperature sensing for permanent magnet machine air gap by composite Terfenol-D fibre bragg grating sensor

Abstract

This article evaluates the feasibility of applying a Fibre Bragg Grating (FBG) sensor integrated with Terfenol-D magnetostrictive composite powder material to facilitate simultaneous observation of thermal and magnetic conditions in permanent magnet (PM) motors for condition monitoring purposes. The sensor design, calibration and measurand interpretation methods are first presented. The paper then reports experimental tests performed on a purpose-built PM rotor test rig instrumented with the proposed FBG composite flux sensor. The experimental results demonstrate that the sensor's measurements contain simultaneously obtained information on the thermal and magnetic conditions in the sensor location. The multiphysical thermo-magnetic sensing can be clearly differentiated based on the electric machine application inherently different dynamics of individual physics.