The megawatt high-power permanent magnet direct-drive generator is the main trend of wind power development. The rationality of design of the generator's cooling system is an important index to evaluate the reliability of the permanent magnet generator. Aiming at solving the problems of large generator volume

cooling difficulty

high dissipation heat power and permanent magnet being easy to suffer irreversible demagnetization at high temperatures in high-power permanent magnet direct-drive generator

a stator pipeline-circulating watercooling system for 3.2 MW modular permanent magnet direct-drive wind turbine generator is designed. Moreover

by using fluid-solid coupling method

the temperature calculation model is established to study the design law of the cooling system

it was compared with the traditional shell-type water-cooling scheme and the stator-slot aircooling scheme. The results show that

when the outer rotor structure is adopted

the cooling pipeline should be close to the stator

and the temperature uniformity of the water-cooling method is better than the air-cooling method

indicating the water-cooling method has better cooling effect. In this design

the maximum temperature gradient is low and the temperature difference between the inlet and outlet fluids is small

which is conducive to the heat dissipation of equipment other than the motor

but the economy is slightly poor.