Managing Embedded Generation Integration: Challenges and Solutions for Distribution Substation Earthing

The transition towards distributed generation (DG), particularly renewable energy sources, has become increasingly important in recent years with the potential benefits of reducing carbon emissions and improving energy security. However, one of the key technical challenges associated with the increased introduction of DG into the grid is the potential impact of the effectiveness of the substation earth mat. The associated increase in fault level associated with DG integration coupled with the deterioration of the earth mat over time could result in a scenario where the touch and step voltages at a substation may be at a level that pose a risk to the safety of staff. The authors will, utilizing a case study, examine the impact of increased DG on the touch and step potential at a distribution substation. When found to exceed acceptable levels, the paper discusses the challenges associated with modifying an existing earth mat and potential solutions to mitigate this risk.