Fault Identification of High-voltage Cable Sheath Grounding System Based on Ground Current Analysis

In order to reduce the induced voltage of the metal sheath of the high-voltage cable, the metal sheath of the high-voltage cable is usually cross-connected in the transposition box of the cable cross-interconnection. In the process of reconnecting the cable line, the transposition is easy to be connected backwards, or even wrong. In addition, there will be many situations such as moisture, water intrusion, external force damage, resulting in cross-interconnection failures in the metal sheath of the high-voltage cable. Cross-connect faults need to be dealt with in time. The paper analyzes the cross-connect faults of 110kV XLPE high-voltage cables, and uses PSCAD electromagnetic transient software to model and simulate. Simulation results summarize the characteristics of grounding current changes under different sheath faults. The results can provide a theoretical basis for the fault detection of the cable cross transposition system.