Research on Multiparameter Detection for Transformers Based on FBG Sensing

To address the issues of single-parameter detection and insufficient anti-interference capability in the condition monitoring of oil-immersed transformers, this paper proposes a multiparameter synergistic detection method based on Fiber Bragg Grating sensing. By designing a flow-rate-temperature composite sensor and a pressure sensor, simultaneous detection of transformer oil flow rate, temperature, and pressure is achieved. The flow-rate-temperature sensor employs a target-disc and dual-FBG symmetric packaging structure, separating the effects of strain and temperature using the differential grating method. The pressure sensor utilizes a beryllium bronze diaphragm with dual-grating temperature compensation to eliminate environmental interference effectively. Experimental validation on a custom platform shows: in the temperature calibration test, the linear fitting degree between FBG wavelength shift and temperature exceeds 0.996; after temperature compensation, the pressure sensor achieves an average sensitivity of 13.83 pm/MPa with a maximum error of only 0.0888 MPa; in the flow-rate-temperature composite test, the maximum flow rate detection error is below 0.073 m/s, and the maximum temperature error does not exceed 0.76°C. The proposed method solves the limitations of traditional single-parameter detection through multiparameter distributed sensing, providing technical support for transformer condition evaluation and demonstrating engineering application potential.