As the line load continues to rise

more and more single-core cable lines adopt the operation mode of same-phase multiple parallel connections

and how to evenly distribute the parallel circuit current has always been a key issue restricting the parallel operation of the cable in phase. Through the analysis of circuit topology of the same-phase parallel cable line

the calculation method of sequence impedance parameters of each parallel circuit during the in-phase parallel operation of the high-voltage cable is given. Then

the mirror layout scheme can be used to achieve equal mutual impedance between the same phase parallel cables

so as to obtain a uniform flow effect in cables. On this basis

supported by a new 500 kV substation project

finite element method is used to calculate the current distribution characteristics of two parallel running lines of the same phase of the single-core cable under different spatial layout schemes. The calculation results show that the mirror layouts can effectively reduce the unbalanced distribution parameters and improve the utilization of high-voltage single-core cable. Finally

combined with the outlet conditions of the conventional underground or semi-underground 500 kV GIS substations

the recommended layout scheme for parallel operation of two cables in the same phase is given.