Comparison of conventional bearing with magnetic bearing for direct drive wind turbine

Abstract

Direct drive machines are heavy and expensive for large wind turbines. The use of magnetic bearing has a possibility of reducing the weight of the direct drive machine. However the magnetic bearing itself adds weight and losses in the system. This paper compares the conventional bearing used in state of art Zephyros Z72 wind turbine with a comparable magnetic bearing system in terms of weight and losses. Comparison shows that magnetic bearings are 22% heavier compared in comparison to conventional bearing and the losses are comparable.