Implementation of a Fiber-Wrapped Polymer Mandrel Acoustic Emission Sensor

Fiber-optic sensors show advantages in acous- tic emission (AE) detection of power equipment due to their galvanic isolation and immunity to electromagnetic interference (EMI). This paper proposes a fiber-wrapped polymer mandrel (FWPM) acoustic emission sensor based on the Mach-Zehnder interferometer. The mechanism model of the sensing head is established using displacement function and state equation. The finite element analysis shows that the wrapped length of the optical fiber, the geometric parameters, and the mechanical properties of the polymer mandrel affect the frequency response of the FWPM AE sensor. The theoretical analysis and experimental results show that the proposed sensor is sensitive to 30–200 kHz AE waves and has good linearity. The FWPM AE sensing system has a lower detection limit than the piezoceramics (PZT) sensing systems. The FWPM AE sensing system is expected to provide significant support for solving the health monitoring of ultra-high voltage (UHV) equipment.