To design long-distance 330 kV cable line rationally and standardly and provide selection basis of the devices such as cable sheath protector

two cross-connection modes of the 330 kV cable sheath are studied.Firstly

according to the existing 330 kV cable parameters and laying method of cable in tunnel

the electromagnetic transient analysis software EMTP-ATP is used for simulation modeling

and the sheath ’ s induced voltage of each point of the line in normal operation is analyzed to obtain the voltage ’ s distribution laws and characteristics for two sheath grounding modes.Secondly

in the case that a single-phase short-circuit grounding fault occurs in the system

the features and distribution laws of the sheath’s induced voltage waveforms of the faulty line and normal line are discussed.The induced voltage data under the two grounding modes are compared

and the effects of the line length on the distribution law and the value of the induced voltage are analyzed.Thirdly

a return cable layout method is proposed for the single-end protected grounding mode

and the influences of the additional return cable and the return cable relocation on the system are investigate.It is concluded that the direct grounding mode at both ends of the sheath has relatively low induced voltage in steady state and transient fault state

and has high economical efficiency

so it can be taken as the preferred grounding mode for the 330 kV cable sheath.For the single-end grounding mode

the addition of return cable can reduce the induced voltage of the cable sheath when fault occurs

and return cable relocation can reduce the circulating current during steady-state operation.