双馈电机超同步运行转子电路复功率的负频率分析法

Rotor Power Analysis of Doubly-Fed Induction Machine During Supersynchronous Speed Using Minus Frequency

针对文献中双馈电机超同步运行时转子电路频率为负值还是其绝对值的不同观点,分析了产生这种分歧的原因,指出了采用负频率的必要性和合理性。分别采用统一时空矢量图计算法和等效电路计算法分析了负频率正弦电路的无功功率特点,并将分析结果应用到双馈电机超同步运行转子复功率分析中,指出应用等效电路计算转子功率时的"无功功率变性"现象。相应的实验结果证明本文所采用的分析方法和所提出的"无功功率变性"观点是正确的。

There are different ideas whether the rotor frequency of doubly-fed induction machine（DFIM） during supersynchronous speed should be minus or plus.This paper analyses the rotor circuit and proposes that minus frequency is necessary.The feature of minus frequency sinusoidal circuit is researched by means of unified space-time vector and equivalent circuit and applied in rotor power analysis during supersynchronous speed.The rotor reactive power calculated based on the DFIM equivalent circuit might be inductive or capacitive.This character should be judged not only by the sign of reactive power,but also the sign of rotor frequency.A conclusion named ＂reactive power character reverse＂ is obtained.The result of experiment proves that the analysis method and conclusion in this paper are correct.