Comparative study on winding materials for wind turbine alternators

The demand for electricity generation from wind energy is increasing day by day. However, wind turbine manufacturers face various difficulties in the design and production stages, such as increasing energy efficiency, providing higher power generation at smaller sizes, reduction in weight, increasing reliability, ease of production and decrease in the costs to produce more efficient and more powerful machines. In this paper, the selection of winding material in synchronous machines used in wind turbines and effects on the output performance of the machine are discussed. Usage of low-density material instead of copper (Cu) was comparatively analyzed to reduce the total mass and cost in design stages. The advantages and disadvantages of the usage of aluminum (Al) as a winding material compared with a copper winding structure were investigated, which may be an example of cost savings for alternator structures in wind turbines. The total weight was reduced with the aluminum coils placed in the same slot area without any dimensional modification in the alternator. Both copper and aluminum winding structures were investigated by analyzing these in terms of weight, power density and cost. The results obtained here are recommended for wind turbine manufacturers.