Optimal design improvement of two neighbouring distrubution substation by compression ratio methods in power system

This paper presents touch voltage reduction technique for uniform and two-layer soil by applying grid compression ratio. The design of ground grid is discussed pertinent to its maximum touch and step voltage produced for a given GPR. The parameters are analyzed to ensure that they conform to the IEEE 80-2000. It is found that, for a given GPR, the maximum touch and step voltages of the rectangle grid, regardless its compression ratio, are lower than the square´s. This means rectangle grid is safer than square one. The shape of ground grid is therefore one of the crucial factors in grid design, especially when grids are placed close together unconnected. This is the case when a new substation is constructing near one which is still energized. When there is a GPR, the touch voltage will be made worse by the two unconnected grids, and thus harm and damage personnel and sensitive equipment.