考虑阻尼绕组约束能量变换器空载电动势波形的分析

Analysis of Powerformer No-Load EMF Waveform With Different Damper Constraints

电机的阻尼绕组端部联结方式的不同,使得阻尼条中感应涡流的约束不同,引起阻尼绕组电流的分布不同,从而对气隙磁场和空载电动势产生影响。本文提出了场路耦合时步有限元法来计算凸极同步电机空载电动势波形,针对能量变换器样机,进行了考虑不同阻尼绕组约束条件下的空载电动势波形的计算,并对计算结果和实验值进行了比较。结果表明,阻尼绕组约束不同,能量变换器空载电动势谐波含量不同,电动势波形的正弦畸变率也发生一定的变化,精确计算时需要考虑这种变化。

The constraints to eddy current induced in damper bars is different because of the different connection for the damper end winding of electric machine, and the current distribution of damper winding is also different. These make effects on the air gap magnetic field and no-load EMF. For the powerformer prototype machine in this paper, field-circuit coupling time-stepping FEM is proposed to calculate no-load EMF waveform of salient pole synchronous machine under different constraints for damper end winding. Then the results are compared with the experimental results. It shows that different constraints on damper winding produce different harmonic content in no-load EMF waveform of powerformer. The sine distortion factor also changes in some extent, and this changes need to be considered in accurate calculation.