异步电机高频杂耗的自适应时步法有限元计算

异步电机杂散损耗的准确计算是一个十分困难的问题。本文论述了对非斜槽异步电机高次谐波杂散损耗的计算方法。文中采用的数学模型把电磁场有限元方程与电路方程耦合在一起,当输入电压波形给定后,电机中的之流和磁密波形可通过时步法直接求得。根据计算所得的高次谐波电磁场,就可进一步计算出高次谐波杂散损耗。计算结果通过样机试验得到验证。在计算中采用了自适应时间步长的方法,并首次提出了一种估计局部截断误差简单实用的方法。

Computation of Harmonic Stray Losses of Induction Motors Using Adaptive Time Stepping Finite Element Method

The precise computation of stray losses in induction motors is still a difficult problem. This paper describes a method for evaluating harmonic stray losses in non-skewed induction motors. The model couples the finite element electromagnetic equations with the electrical circuit equations. When the applied voltages are known, the stator current waveforms and the magnetic vector potential waveforms can be solved directly by time stepping method. Then the harmonic stray losses are evaluated according to the distribution of the harmonic fields. In the computation, the adaptive time stepping method is explored. A new simple method to estimate the local truncation error at each time step is presented.