Cable Intermediate Joint Crimp Condition Assessment and Early Failure Warning: An All-Fiber Approach and Application

In this study, we proposed an innovative method for fault assessment and early warning in fiber optic cables. This approach utilized fiber optic temperature sensors to identify crimping defects in cable joints and issue warnings in the event of impending faults. The aim was to monitor the state of cable intermediate joint crimping accurately. By utilizing fiber-optic sensors, we directly measured the internal joint temperature, thereby effectively mitigating the impact of external environmental factors. To further investigate the relationship between temperature data and crimping conditions, we established a model based on the correlation between temperature and current, incorporating principles of thermal conductivity. Based on this model, some quantitative conclusions were drawn, such as the typical characteristic temperature difference for a crimp failure with ${k} = 2.36$ being $10.2~^{\circ }$ C, and the ${R} ^{{2}}$ of the fit curve for the determination of the magnitude of the load capacity and the degree of crimp failure was 0.9988. This method enables precise identification of crimping imperfections and early fault detection. The feasibility and accuracy of this method were verified through experiments, using 110 kV silicone rubber integral prefabricated intermediate joints as a case study. This research contributed a novel solution for monitoring and maintaining cable intermediate joints, exhibiting significant practical application value.