Simulation of Power Frequency Overvoltage of 500kV Parallel Cable Sheath in Single-Ended Grounding

In the 500kV high voltage single-core cable system of short cable length, metal sheaths are generally grounded at one terminal. The overvoltage occurring in the metal sheath of 500kV parallel cables is closely related with its complicated running condition and the wiring mode. The purpose of this study is to evaluate the protection capability of 500kV high voltage single-core parallel cables when exposed to overvoltage intrusion. The simulation and calculation of power frequency overvoltage were carried out for the 500kV high voltage single-core parallel cables running under typical working conditions. Specifically, the effects of cable length, short circuit, earth resistivity, load resistance, model parameters on power frequency overvoltage of metal sheaths are analyzed. The results show that, under the single-ended grounding, the operation conditions such as the cable length, location and type of short circuit, load resistance exhibit a significant effect on the maximum value of overvoltage in the metal sheath, while the earth resistivity shows a small effect on the maximum value of overvoltage.