Multi-Physical Field Analysis Of High-Capacity Squirrel Cage Asynchronous Wind Power Generator

The squirrel cage asynchronous wind generator has the advantages of simple structure,compact structure,high reliability and easy installation and maintenance.It can meet the harsh environment conditions such as humidity and salt fog in offshore wind farm,and has been widely used in offshore high-capacity wind power generation system.Taking the 4.25 MW squirrel cage asynchronous wind generator as the research object,electromagnetic field analysis of large capacity squirrel cage induction wind generator was carried out,and the fluid field and temperature field of the motor were analyzed combined with the basic principles of fluid mechanics and heat transfer.Firstly,combined with the core structure and winding form of 4.25 MW squirrel cage asynchronous wind generator,the electromagnetic and loss of the motor are analyzed.The 2D finite element model of the motor was established in the ANSYS Maxwell electromagnetic finite element analysis software.The electromagnetic field simulation of the motor was carried out,and the motor loss data were obtained.Then,according to the ventilation system structure of the motor,the equivalent air-flow network model was established.The influence of different rotor structures on the fluid field of the squirrel cage induction wind generator was analyzed based on the equivalent wind path network model.Three dimensional fluid model of motor was established.Three dimensional fluid field simulation of motor was carried out with CFD software.The distribution of the flow and pressure parameters of the motor ventilation system was calculated,which is used as the model parameter and boundary condition in the temperature field analysis of the motor.Finally,according to the structure characteristics of the motor,three dimensional fluid-solid coupling models of the air inlet side winding end of the motor,the region within the iron core,the air outlet side winding end and heat exchanger were established.The temperature field of each part of the motor was simulated,and the temperature field of the motor under different conditions was analyzed.The internal heat transfer law of the motor was summarized.