间谐波相序特性的研究

相序是三相电力系统中电压和电流的重要特性。为了认识间谐波的相序特性，文中以两种典型的间谐波源(变频驱动装置和电动机)为例，通过理论分析和实验探讨了它们产生的间谐波的相序。研究表明间谐波可以表现为正序或负序。但是间谐波的相序特性不同于谐波，同一频率的间谐波可以具有不同的相序。一般规律是：间谐波的相序与被调制的系统基波(或谐波)分量的相序相同。如果调制后得到的频率为负值，则间谐波信号的相序将变反，即由正序变负序或由负序变正序。文中的研究成果有助于深入认识间谐波的特性和发展间谐波仿真软件。

STUDY ON THE PHASE SEQUENCE CHARACTERISTICS OF INTERHARMONICS

Phase sequence is an important attribute of voltages and currents in three phase power systems. In order to explore the phase sequence characteristics of interharmonics, two typical interharmonic sources (variable frequency drives and motors) are taken as examples, and the sequence of interharmonic components produced by them are investigated through theoretical analysis and experiments. The results reveal that interharmonics can have either positive or negative sequence. But the phase sequence characteristics of interharmonics are different from those of harmonics, i.e., interharmonics with the same frequency may have different phase sequence. The general rule is that the sequence of interharmonics is the same as that of the supply system components being modulated. If the modulated frequency is negative, the sequence of the corresponding interharmonic component will change from positive to negative or vice versa. The research will help to improve our understandings on the characteristics of interharmonics and can be useful for the development of interharmonic simulation programs.