Influence of capacitive parameters on the overvoltage characteristics of three-core submarine cable

Over-voltage in submarine cable plays an important role in the cable failure and the collapse of the connected power system. Previous studies focused on the effects of circuit parameters of power transmission line on over-voltage characteristic. However, in the case of long distance submarine cable, the effects of cable parameters, especially for capacitive parameters can not be ignored. In this paper, the influence of capacitive parameters on the over-voltage characteristics of a 35 kV three-core submarine cable is studied. A simulation model is constructed by PSCAD/EMTDC software to calculate the transient over-voltage and over-current characteristics under the fault conditions. Particularly, the relative permittivity of the insulation layer and the reactive compensation are carried out. The results show that when the line operates with no load, the terminal voltage rise and reactive power increase with the increase of the relative permittivity of the insulation material. The single-phase grounding fault gives rise to a 1.5 times overvoltage amplitude and an overcurrent of 860 A. In addition, 1100V over-voltage will be induced on the metal sheath of the submarine cable. With an increase of relative permittivity, the overvoltage value caused by the single-phase grounding increases.