The protective chamber placed the secondary equipment in digital substation is placed close to primary equipment

and the normal operation of the secondary equipment in the protective chamber may be affected by the primary equipment. Researching on the influential factors of potential in protective chamber

this article analyzes the effect of potential in protective chamber when the position of transmission line is changed

the grid size of metal mesh covering the protective chamber is varied and the thickness of the wire which constitutes the metal mesh is altered by FEM. In addition

this article also compares the shielding effectiveness of protective chamber with different insulation materials and the results shows that:the farther the horizontal distance between the power lines and the chamber

the higher the potential inside the chamber; when the size of metal mesh grid is smaller

the cross-section area of the wire mesh is smaller and the relative permittivity of the insulating material is larger

then the potential inside the chamber is lower. The results provide a theoretical foundation for the construction.