确定自起动永磁电机最小转矩的时步有限元仿真实验方法

Time-stepping Finite Element Simulation Experimental Method of Determining Line-start Permanent Magnet Motor Minimal Torque

自起动永磁电机的最小转矩是评价其启动能力的一个重要指标,根据解析方法所得的光滑转矩–转速(T-s)曲线虽然可得到其具体数值,但其计算条件与实际起动过程差别很大;能够准确反映诸多实际影响因素的时步有限元计算得到的T-s曲线是急剧波动的曲线,据此难以获得最小转矩的具体数值。该文研究工作的目的在于,不对该转矩曲线进行人为处理而获得最小转矩。首先研究在什么计算条件下能得到反映出最小转矩影响的转矩曲线,揭示了在某些计算条件下可能出现的最小转矩被"淹没"的现象;进而提出用以确定最小转矩的优化加载时步有限元仿真实验方法。通过将实例计算所得转矩曲线与实测曲线对比,表明计算结果可信。

The minimal torque （Tmin） of a line-start permanent magnet motor （LSPMM） is one of the most important indexes evaluating self-startup ability. The value of minimal torque can be obtained from smooth torque-speed curve （T-s） according to approach method; but there are many differences between the calculation condition and the actual condition in the starting process; The finite element method （FEM） which can consider the many practical factors could give a much more accurate T-s curve, but it is difficult to obtain the specific Train value for the curve is fluctuating tempestuously. The research work of this paper aims to obtain the Train without subjectivity manipulating T-s curve. Firstly, this paper made a study of calculation condition under which torque-speed curve reflecting the minimal torque influence could be obtained, and revealed that the minimal torque was possibly ＂submerged＂ under some conditions; and then, the optimized loading finite element method experimental method was proposed to determine the minimal torque. Comparison of the curves calculated and measured indicates that the calculation result is believable.