Dimensioning of Sheath Voltage Limiters for Single-Core Power Cables Connecting an Overhead Transmission Line to a 150 kV Substation

This case study evaluates the stresses of sheath voltage limiters installed at the open end of single-point bonding systems employed for two single-core power cable circuits (lengths: 120 m and 50 m). These cable circuits connect one circuit of a 150 kV double-circuit overhead transmission line to a 150/33 kV substation. Detailed simulations are performed using the ATP-EMTP software for four main scenarios: (i) steady-state operating conditions, (ii) single-phase and three-phase short circuits, (iii) lightning strikes to towers, and (iv) shielding failures at the incoming 150 kV overhead line. For the lightning-related scenarios (iii and iv), the residual voltage and the surge current through the sheath voltage limiters are computed, considering the effects of the instantaneous value of the AC operating voltage, the time to half value, and the amplitude of the lightning return- stroke current. Stress on the sheath voltage limiters is analyzed in terms of charge transfer and specific energy obtained through simulations. Finally, the minimum required characteristics of the sheath voltage limiters are determined and discussed in the context of appropriate dimensioning in engineering applications.