Fiber Bragg Grating Sensing for Condition Monitoring of Power Electronic Devices: A Review

Junction-temperature cycling and the associated thermo-mechanical stresses strongly affect the reliability of power electronic (PE) devices, but conventional sensors are challenged in providing accurate measurement of related localized stresses due to limited electrical insulation, size limitations and poor electromagnetic interference (EMI) immunity. Fiber Bragg grating (FBG) sensors have emerged as a promising solution because of their miniature size, excellent insulation, high bandwidth, and multiplexing capability. This review summarizes recent progress in applying FBG sensing to the condition monitoring of PE devices, detailing bonding strategies, sensor placement, and strain–temperature decoupling across different monitoring schemes, while also examining the effect of airgaps, residual stress, and grating length on the measurement accuracy and dynamic response. Building on the reviewed state of the art, the FBG-based approaches for device ageing assessment and the remaining challenges in this area are discussed.