自带风扇冷却的永磁电机热计算方法对比分析

Comparison and Analysis of Thermal Calculation Methods for Fan-cooled Permanent Magnet Motor

为了对比分析不同热计算方法在电机热设计和工程应用上的可行性,文章以一款自扇风冷永磁电机为研究对象,对其风扇工作流量、电机流体场和电机温升进行分析。分别采用解析法与有限体积法对电机风扇的额定工作风量进行计算,并通过有限体积法得到了电机整体流体域的速度分布;基于流体计算,分别采用等效热路法与有限体积法对电机温升进行预估。通过对比计算值与实测值,说明两种方法均有一定的可信度,其中有限体积法方法更适于电机的设计改进与优化,解析法可用于派生电机设计和方案初步评估。

In order to comparatively analyze the feasibility of different thermal calculation methods on thermal design and engineering application of motor, based on a fan-cooled permanent magnet motor, it analyzed the flow of fan, the fluid field and temperature-rising of motor. Moreover, it calculated the rated air flow of motor fan with analytic method and finite volume method （FVM） and then the achieved velocity distribution of fluid field. On the basis of fluid calculation, it respectively used equivalent therrr al path method and FVM to estimate the temperature rising of motor. Through comparing calculation value and practical value, it proved that the two methods had certain reliability. FVM is more suitable for the improvement and optimization of motor design, and thermal model method can be used for subseries motor design and preliminary design evaluation.