Transient Characteristic Analysis and Parameter Optimization of Sheath Voltage Protector for Large-length High Voltage Cable

摘要

Large-length high voltage (HV) AC cable requires elevated sheath voltage protector (SVP) performance. A simulation model for typical 220 kV HV cable system with two different grounding methods was established by PSCAD software. Based on this model, the role of cable length on the transient characteristics of sheath induced voltage was analyzed, and four optimized ways to improve the absorptive capacity of SVP were proposed. The cable length dependence of allowable short-circuit current of optimized SVP was obtained. It is shown that the allowable cable length under 20 kA short-circuit current increases to 2700 m (single-terminal grounding) or 3500 m (cross-bonding grounding). In this way, the overvoltage safety of large-length HV cable can be guaranteed by optimized SVP.