A New Brushless Non-salient Pole Generator with Multi-pole Rotor for Direct-drive Wind Turbines

Wind turbines provide up to 10% of all electricity in Europe, making a significant contribution to save the ecology. In case of high reliability of wind turbines and low maintenance, the cost of electricity can be lower than that of fossil fuel power plants or nuclear power plants. A new type of brushless monopolar generators with a field winding on the stator provides a simple design and high reliability due to the absence of rings and brushes on the rotor. One of the ways to improve reliability is to exclude the gearbox from the design of the wind turbine, but this leads to a decrease in rotational speed of generator's rotor. This article describes the design of the multi-pole brushless generator for use at infra-low rotor speed of 25 rpm. The output frequency of 50 Hz allows to work directly on the load and through a converter, while the dimensions of such a generator itself stay the same.