Interdigital Capacitor Sensor-Based Cable Health Monitoring

This article proposes a novel diagnostic and prognostic approach that combines interdigital capacitor (IDC) sensors with extended Kalman filter (EKF) to estimate the insulation degradation and predict the remaining useful life of cables. In the proposed approach, the degradation process of cable jackets is monitored by an external surface IDC sensor. The design of highly sensitive IDC sensors for thin cables is challenging because of cable's limited circumference. A new design method is used to optimize IDC sensors for thin cables, which can achieve high sensitivity with fewer but longer electrodes. The sensors are fabricated on flexible substrate and conformed on thin cables that are undergone accelerated aging tests. The capacitances at different aging levels are measured, and from there a degradation model is established for diagnosis and prognosis. With this degradation model, an EKF-based fault diagnostic and prognostic approach is developed. A series of experiments is conducted to demonstrate the effectiveness of the proposed method.