Safe Grounding Grid Design for HVDC Converter Station

The main goal of this paper is presenting an optimum and safe design for the proposed high voltage direct current (HVDC) grounding grid for converter station at Badr city in Egypt for uniform and non-uniform soil resistivities. Also, the paper discusses the difference between HVDC grounding grids and high voltage alternating current (HVAC) ones. CYMGRD software was used to estimate the step and touch potentials at the soil surfaces at different conditions. The consequences show that the computed results for step and touch potentials are below the safe limits for human in cases of continuous normal and fault conditions for uniform and non-uniform soil resistivities. From results, touch voltage in a non-uniform layer in continues operation is 17.65 V, and equal to 57. 37V in fault operation.