Ventilation structure design and heat transfer analysis of 3.3 MW permanent magnet direct drive wind generators

For megawatt permanent magnet direct drive wind generator, with the increase of its power level, the insulation of the motor may be threatened by the increase of operating temperature, which may also lead to the irreversible demagnetization of permanent magnets. To solve this problem, a radial forced ventilation cooling structure was designed and established in this paper, based on a 3.3 MW, 12 rpm external rotor surface mount permanent magnet motor. The coupling relationship between electromagnetic field and temperature field is reasonably considered by iterative simulation method, and the temperature field and fluid flow are analyzed based on fluid–structure coupling method. The results show that the ventilation structure designed in this paper has a certain cooling effect and can meet the needs of its safe and stable operation. It has a certain reference significance for the cooling system design of megawatt permanent magnet direct drive wind generator.