Fiber-based Current Monitoring
With the usage of insulated HVAC power cables, a comprehensive monitoring solution is becoming increasingly important - one that computes cable ratings based on thermal profiling (RTTR), detects and locates cable hotspot temperatures (Distributed Temperature Sensing - DTS), as well as cable faults and Third Party Intrusion (TPI) events (Distributed Acoustic Sensing - DAS). Additionally, permanent electrical condition monitoring of cable accessories and terminations is gaining traction for early detection of issues within the entire cable system. AP Sensing, together with Brugg Cables, performed a study to measure sheath currents with the aim of electrical condition monitoring of the operator's asset.
AP Sensing's sheath current monitoring solution (Fiber-based Current Monitoring - FbCM) was implemented to minimize the risk of unexpected downtimes. These downtimes can be caused by link box faults such as a defective sheath voltage limiter (SVL) or cable sheath damages resulting from unexpected ground contact as a consequence of TPI events such as digging.
AP Sensing's monitoring solution was deployed successfully on the longest HV cable installation in Switzerland. The 110 kV AC cable is 32 km long with 35 cable joints and five major sections. Our FbCM solution is installed on all three sheath current cables at two cross-link boxes of two major sections.