Designing Earthing Systems for Onshore Wind Farm Sites

With the demand for renewable power generation increasing and with public pressure stressing a viable alternative to the current thermal and nuclear convention, wind generation has been a growing market in the last couple of decades. This technology is relatively new when compared to the latter implementations and it therefore comes with several challenges. This investigation focusses on designing earthing systems for these wind farm sites and the procedures behind reducing any fault current and consequently large potentials that arise on site and become a threat to human life and damage equipment on site. This project analyses two wind farm sites, namely Wind Farm A and Wind Farm B. It is noticeable from the Rise of Earth Potential calculations that the first is considered a COLD site as it has a maximum voltage less than 430V (for fault duration greater than 200ms) while the latter is a HOT site as the maximum voltage surpasses that limit. This difference in potentials ultimately affects the earth grid design as it’s evident the HOT site requires a lot more earthing tools in order to lower the ground potential to acceptable limits. The achievement of all the objectives established prior to commencing the project suggests this investigation can be considered successful. Designing Earthing Systems for Onshore Wind Farm Sites January 2014 iii Table of