On-line Diagnosis and Location of High Voltage Cable Sheath Fault Based on Sheath Current

摘要

Long-distance cables are often damaged by external forces due to site construction, resulting in protective layer grounding fault. Conventional fault location and detection methods, such as bridge method and traveling wave method, require on-site measurements along the cable, which results in heavy maintenance workload. For this reason, a method of online diagnosis and location of high-voltage cable based on sheath current is proposed. The simulation results show that when a fault occurs, the sheath current will change with the change of fault location and grounding resistance. Therefore, the external insulation faults of cables can be monitored, diagnosed and located on-line based on sheath current.