Double-optical-fibre Temperature Compensation Method Used for Interface Pressure Measurement Between Cable and Accessory at High Temperatures

Interface pressure between cable and accessory is closely related to the safe operation of cable accessory. By means of an external optical fibre Bragg grating temperature-compensated curvature sensor, the paper proposed a new method for on-line measurement of interface pressure between cable and accessory at high temperatures. First, based on the fibre Bragg grating sensing mechanism, pure bending mathematical model, and thick-walled cylinder model, a fibre Bragg grating temperature-compensated curvature sensor was fabricated by using Dowcorning Sylgard−184 silicon rubber. Then, the interfacial pressure values of 10 kV cable accessories at room temperature and high temperatures under different expansion rates were measured. The measurement results show that the temperature compensation measurement deviation of the fiber grating curvature sensor is between −7.74% and 7.01%, and the interface pressure between cable and accessory gradually increases with the increase of temperature (from 30 °C to 60 °C), and the test results are consistent with the measurement results of traditional piezoelectric sensors. This method is hopeful to evaluate the long-term reliability of the interface pressure of cable accessories operating in complex temperature environments. © 2023 Science Press. All rights reserved.