Structural Design And Optimization Analysis Of 3MW Direct-Drive Double Stator Brushless Doubly-Fed Wind Power Generator

The shortage of fossil energy and the problems of environmental pollution have become increasingly serious,but that promote the rapid development of new energy technologies.Wind energy has been paid more attention to because of its abundant resources,renewable,clean and pollution-free.And in all renewable energy technologies,wind power is the most mature,the most large-scale and commercial development prospects,thus the wind power technology is developing rapidly.Double stator brushless doubly-fed generator as a new alternator,with the advantages of brushless reliability,direct drive,low variable frequency capacity,variable speed constant frequency and the diversification of operation,has broad application prospects in the field of wind power.In this paper,3MW double stator brushless doubly-fed generator is taken as the research object,designing its overall structure and optimizing the important structure.The main contents of this paper are as follows:Firstly,this paper,on the basis of in-depth study of the structures of different wind turbines,designs the whole structure according to the particularity of double stator brushless doubly-fed generator.And then some important structure and connection ways are analyzed.Secondly,optimizating the magnetic-isolation ring and stationary axis.Basing on the optimization of the dovetail groove of magnetic-isolation ring,doing size optimization of magnetic-isolation ring to reduce the weight and the manufacturing cost.Due to the overall larger size,The stress in core structure of the solid stationary axis is too small.The solid stationary axis can not effectively use the material of core structure,so use hollow axis structure to instead of itself.And then doing size optimization of it to meet the strength requirements.Finally,the front axle flange,the rear support plate and the inner-stator supporting plate are optimized.On the basis of topological optimization of the front axle flange,doing sensitivity analysis of its structural parameters,then selecting important structural parameters to do size optimization of the front axle flange.As the important supporting structure of the rotor end,its good or bad design of the rear support plate has a direct impact on the balance of the air gap,so doing size optimization of the rear support plate to meet the requirements of a certain rigidity.In order to improve the first-order modal frequency of the rotor core structure composed of the magnetic-isolation ring,the front axle flange and the rear support plate,the schemes between the front axle flange and the rear support plate with different number of stiffener is compared and analyzed.And The optimal scheme is selected to improve the first-order modal frequency of the rotor core structure.The inner stator support plate is optimized to reduce its weight and increase its first-order mode frequency.In this paper,the overall structure and structural optimization of the MW-type direct-drive double-stator brushless doubly-fed generator are studied systematically,which is of great significance and practical value for structural design and structural optimization of large-scale wind turbines.