Numerical and Experimental Modelling of Gas Flow and Heat Transfer in the Air Gap of an Electric Machine. Part II: Grooved Surfaces

The study deals with the cooling of a high-speed electric machine through an air gap with numerical and experimental methods.The rotation speed of the test machine is between 5000-4000 r/rain and the machine is cooled by a forced gas flow through the air gap.In the previous part of the research the friction coefficient was measured for smooth and grooved stator cases with a smooth rotor.The heat transfer coefficient was recently calculated by a numerical method and measured for a smooth stator-rotor combination.In this report the cases with axial groove slots at the stator and/or rotor surfaces are studied.Numerical flow simulations and measurements have been done for the test machine dimensions at a large velocity range.At constant mass flow rate the heat transfer coefficients by the numerical method attain bigger values with groove slots on the stator or rotor surfaces.The results by the numerical method have been confirmed with measurements.The RdF-sensor was glued to the stator and rotor surfaces to measure the heat flux through the surface,as well as the temperature.

永磁体涡流损耗的分析

表面式永磁电机永磁体直接与气隙接触,变频供电时产生的较大含量谐波将在永磁体内产生一定的涡流损耗,且由于转子散热较差,将导致永磁体温升较高,容易造成永磁体发生不可逆去磁风险。因此对永磁体涡流损耗的研究有其必要性与重要性。文中针对影响永磁体涡流损耗较大的气隙长度、定子槽口宽度、气隙长度与槽口宽度的配合、永磁体削角等进行分析,通过合理选择电机结构尺寸来降低永磁体涡流损耗,并利用三维有限元法与解析法验证计算规律的正确性。

高压高效电机铜排转子制造中的冲槽切气隙工艺

阐述了能有效降低电机损耗和温升的冲槽气隙工艺,为高压高效电机铜排转子制造提供了一种新工艺方法。

降低压缩机永磁同步电机的振动

以一款存在较大振动的永磁同步电机为例,针对引起电机振动的主要电磁力谐波次数,提出了对定子齿削角、转子取不均匀气隙、提高定子模态频率和转子分段斜极等方法来降低振动。通过样机制作和测试,证明其可有效降低振动。

冲槽切气隙免车转子工艺方法

通过实例阐述了能有效降低损耗及温升的冲槽切气隙新工艺及其优点,并对其工艺特点、工艺方法、设计等进行了介绍,有效地解决了转子车气隙工艺存在的缺点,为中小型电机转子制造提供了一种全新的工艺方法。

大型增安型异步电动机铜条转子制造中冲槽切气隙工艺的应用

通过实例阐述了能有效降低损耗及温升的冲槽切气隙新工艺的优点,并对其工艺特点、工艺方法、模具设计等进行了介绍,很好地解决了转子车气隙工艺存在的缺点。为大型增安型电机转子制造提供了另一种工艺新方法。