具有自调节通风性能的大型永磁同步发电机内流热特性数值研究

Numerical Study of Internal Flow Thermal Characteristics of Large Permanent Magnet Synchronous Generator with Self-Regulating Ventilation Performance

为了探究具有自调节通风功能的结构紧凑型大型永磁同步发电机内部流体流变特性及温升分布规律,以一台6 MW永磁同步发电机为例,基于电机学和数值传热学理论,结合流-热耦合机理,根据电机实际冷却结构选择一个周期作为求解域,建立三维流体场与温度场耦合分析数学模型及物理模型.采用有限体积元法对永磁同步电机三维温度场进行数值研究,对发电机定转子铁心、定子绕组与绝缘以及永磁体的温升分布特性进行详细分析.通过与电机绝缘温升限值的对比分析,验证了其求解方法的合理性以及计算结果的准确性,为永磁同步发电机温升的计算及通风结构的设计提供参考依据.

In order to explore the internal fluid rheological characteristics and temperature rise distribution of large compact permanent magnet synchronous generator(PMSG)with self-regulating ventilation function,this paper takes a 6 MW PMSG as an example,bases on the theory of electro-mechanics and numerical heat transfer, combines with the flow thermal coupling mechanism,a period is selected as the solution domain according to the actual cooling structure of the generator,the mathematical model and physical model of the coupling of 3D flow field and temperature field are established . The finite volume element method is used to study the 3D temperature field of PMSG,and the distribution characteristics of stator and rotor core,stator winding and its insulation,and permanent magnet are analyzed in detail. The rationality of the method and accuracy of the calculation results are verified by the comparison with and analysis of the ceiling value of the insulation temperature of the motor. This paper provides reference for the calculation of temperature rise of permanent magnet synchronous generator and the design of ventilation structure.