半直驱永磁风力发电机散热性能影响因素研究

Research on Factors Influencing the Heat Dissipation Performance of Semi-Direct Drive Permanent Magnet Wind Generator

[目的]随着风力发电技术的发展,永磁风力发电机单机容量不断增加,发热功率也随之增大,发电机散热正面临前所未有的挑战,如何有效地解决发电机温升高、散热难的问题一直是我们研究的重点。[方法]文章基于STAR-CCM+软件平台建立了发电机散热-冷却一体化数值模拟方法,通过与实验值对比验证了数值计算方法的可靠性。在此基础上对大功率永磁风力发电机内部温度分布规律以及冷却系统散热性能影响因素进行了研究。[结果]在额定功率下,绕组、定子铁芯的最高温度出现在中层区域,工艺条件允许的情况下,冷却水管位置应尽可能靠近绕组,以带走更多的热量;增大发电机总进风量,可显著降低定子铁芯温度和绕组温度;进风温度与绕组、定子铁芯最大温度呈线性关系,进风温度每降低5℃,最高温度降低约1.4℃,降低进风温度可一定程度上改善发电机散热性能;进水温度与绕组、定子铁芯最大温度呈线性关系,进水温度每降低5℃,最高温度降低约3.3℃,降低进水温度可大幅提升发电机散热性能。此外,冷却水管与定子铁芯的间隙极大地阻碍了冷却水管的换热,在间隙中填充导热性能好的材料可有效改善发电机散热性能。[结论]文章所得结论可有效指导永磁风力发电机的散热设计,能够保障风电机组在正常工作中安全运行。

[Introduction]With the development of wind power generation technology,the unit capacity of permanent magnet wind generator is increasing,and the heating power is also increasing.The heat dissipation of generator is facing unprecedented challenges.How to effectively solve the problem of generator temperature rise and heat dissipation difficulty has been the focus of our study.[Method]Based on the STAR-CCM+software platform,an integrated numerical simulation method for generator heat dissipation and cooling was proposed in this paper.The reliability of the numerical calculation method was verified by comparing the calculated values with the experimental values.On this basis,a study was conducted on the internal temperature distribution law and the factors influencing the cooling system heat dissipation performance of the high power permanent magnet wind generator.[Result]Under the rated power,the highest temperature of the winding and stator core appear in the middle area.If the process conditions allow,the cooling water pipe should be as close to the winding as possible to take away more heat.The stator core temperature and winding temperature can be reduced significantly by increasing the total intake air volume of the generator.The intake air temperature has a linear relationship with the maximum temperature of the winding and stator core.For every 5℃decrease in the intake air temperature,the maximum temperature will be reduced by about 1.4℃.Reducing the intake air temperature can improve the heat dissipation performance of the generator to a certain extent.The intake water temperature has a linear relationship with the maximum temperature of the winding and stator core.For every 5℃decrease in the intake water temperature,the maximum temperature will be reduced by about 3.3℃.Reducing the intake water temperature can greatly improve the heat dissipation performance of the generator.In addition,the gap between the cooling water pipe and the stator core greatly hinders the heat transfer of the cooling water pipe.Filling the gap with materials with good thermal conductivity can effectively improve the heat dissipation performance of the generator.[Conclusion]The conclusions drawn in this paper can effectively guide the heat dissipation design of permanent magnet wind generator and ensure the safe operation of wind turbines in normal work.