多相异步电机谐波电流与谐波磁势的对应关系

为了分析定子绕组流过非正弦电流时多相异步电机的运行性能,必须了解谐波电流与谐波磁势的对应关系。通过Fourier级数把非正弦电流分解为基波电流和一系列谐波电流,分别计算各次时间谐波电流所产生的不同次空间谐波磁势,得到谐波电流次数与产生的合成谐波磁势次数间关系且给出通用表达式。结果表明:多相异步电机谐波电流与谐波磁势间的对应关系不同于三相异步电机。分析了某十二相异步发电机未能建立基波电压却建立了谐波电压的原因,并提出了解决方法。

Relationship between harmonic currents and harmonic magneto-motive forces in multi-phase induction machines

Analysis) of the performance of multi-phase induction machines with non-sinusoidal currents in their stator windings requires knowledge of the relationship between the harmonic currents and the corresponding harmonic magneto-motive forces (MMF's). Fourier analysis was used to resolve the non-sinusoidal current into the fundamental component and a series of harmonic components to calculate the resulting MMF's. The relationship between the harmonic currents and the composite harmonic MMF's was derived to yield a generalized expression relating the harmonic currents and the harmonic MMF's. The analysis illustrates that the relationship for multi-phase induction machines differs from that for three-phase induction machines. A twelve-phase induction generator, which produces the 5th harmonic voltage instead of the desired fundamental voltage, is used as an example to verify the analytical results and to develop a method to significantly reduce the 5th harmonic voltage.