Wind farm grounding system analysis

This paper studies a real-case grounding system design for a wind farm and associated equipment. The design is based on the safety criteria provided by Australian and International guidelines listed in the references [1-5]. The wind farm grounding system consists of wind turbine generators, tower base padmounts, 33 kV cable screen and a primary substation. In this paper, grounding system and ground potential rise analyses are presented and discussed. In this study, the conventional earthing system of a wind farm is assessed. The impacts of turbines foundation reinforcement, tower base substation, inter-connection cables and mutual coupling between neighboring turbines grounding systems were simulated. Several methods of improvement are accordingly proposed. Since it is more likely to have farm animals in the vicinity of a wind turbine during the phase to ground fault, a new method for calculation of safe step voltage for farm animals is also proposed.