Mitigation of Induced Currents and Overvoltages in Metallic Sheath of 115 kV Underground Cable Using Sheath Voltage Limiter and Parallel Ground Continuity Conductor

Abstract

The improper grounding technique can cause a high induced current in the underground cable's metallic sheath, leading to the fault event and insulation degradation in the underground cable systems. In this paper, the proper design and selection of the grounding technique, including the installation of a sheath voltage limiter (SVL) and a parallel ground continuity conductor (PGCC) for underground cable systems, are presented. System modeling and simulation are performed using PSCAD/EMTDC software to assess the magnitude of the induced current and overvoltage in the cable systems. The comparative studies and simulation results show that the single-point bonding technique with the installation of the proposed SVL and PGCC rating can mitigate the problem of induced current in the metallic sheath and protect electrical equipment from transient overvoltages effectively.