3MW双馈风力发电机传热特性数值研究

Numerical Investigation of Heat Transfer for 3 MW Doubly-fed Wind Generators

随着风力发电机容量的增加,电磁负荷不断提高,电机的发热问题成为影响机组性能和经济指标的主要因素之一。为了解决该难题,以一台3MW双馈风力发电机为例,根据流体力学以及传热学理论,结合发电机通风性能以及结构特点,建立了发电机三维流动与传热耦合求解的数学模型与物理模型;并给出基本假设与相应的边界条件,采用有限体积法对三维流体场和温度场控制方程进行耦合计算。最后,对发电机内部的流体流动性能、传热特性以及发电机定转子铁心、定转子绕组以及绝缘的温升分布进行了分析,得到端部气体流动不规律以及二次冷却热能力较强等,为更大容量风力发电机综合物理场的准确计算提供了理论依据。

With the increase of wind generator capacity and electromagnetic load,heating problem becomes one of the major factors that would affect the performance and economic benefit of generating set.To solve the problem,a 3 MW double-fed wind generator was taken as an example.On the basis of hydromechanics and heat transfer theory,the mathematical and physical model of 3D fluid flow and heat transfer coupled was established according to structure characteristic of generator.The governing equation of fluid-flow and thermal field was calculated coupled using finite volume method by giving fundamental assumptions and corresponding boundary conditions.Finally,the performance of fluid flow,characteristic of heat transfer,and temperature rise distribution of stator and rotor were analyzed in detail.Some useful conclusions were achieved,by which a theory gist for accurate calculation of synthetic physical fields for the larger capacity wind generator is provided.