Field Evaluation and Testing of Wind Turbine Earthing Resistance: A Case Study of Soetwater Wind Farm

This study focuses on the improvement of wind turbine foundation earthing. Earthing plays a huge role in the wind turbine construction. Thus, failing to adhere to protocols as per IEEE Std 80-2000: IEEE Guide for Safety in AC Substation Grounding may pose serious threat to wind turbines and affect production of electricity. Lightning protection systems (LPS) for wind power generation is becoming an important public issue. Damages and set-backs from breaking down of blades, accidents relating to low-voltage and control circuit breakdowns have been previously recorded from various wind farms around the world due to failure in the earthing system. Effective lightning protection for wind turbines is very important because areas where wind turbines are installed have a high isochronous level. In addition, increasing use of this renewable energy requires high reliability and adequate protection. In this paper, a case study of Soetwater Wind Farm in the Northern Cape Province of South Africa is undertaken to satisfy ground potential rise (GPR) performance criterion for HV and MV earth faults, as well as improvement of earthing to meet the requirements.