外置光纤光栅传感器测量电缆附件界面压力的方法研究

Interface pressure between cable and accessory is the key to ensure the long-term reliable operation of cable accessories. So far, the measurement method of interface pressure is the off-line measurement with the built-in piezoelectric sensor. However, this method not only is difficult to operate, but also damages the interface structure, and the off-line measurement cannot reflect the dynamic changes of interface pressure during the operation of the cable accessory in real time. Therefore, in this paper, a new method for on-line measurement of interface pressure between cable and accessory was proposed by means of an external optical fiber curvature sensor. Based on the pure bending theory, the optical fiber curvature sensor was prepared. Then the relationship model among the outer curvature of the cable accessory, the radial displacement and the inner interface pressure was established. Finally, the interface pressures of 10 kV cable accessories under the different expansion ratios were measured by the calibrated optical fiber curvature sensor. The measurement results show that the optical fiber curvature sensor can be adopted to measure the external curvature of the accessory accurately, and the measurable curvature ranges from 0.033 mm^-1 to 0.05 mm^-1. The measured results of the interface pressure of the cable accessory are basically consistent with the results of traditional piezoelectric sensor measurement.