非正弦周期性负荷扰动引发强迫振荡机理分析

Mechanism analysis of forced oscillation caused by non-sinusoidal periodic load disturbance

电网强迫振荡问题日益突出,负荷侧引起强迫振荡的研究还不够深入。完善了非正弦持续周期性负荷扰动引发电网强迫功率振荡机理的理论推导,对比了冲击性负荷扰动与正弦波负荷扰动引发系统强迫振荡的区别,并分析了影响强迫振荡幅值的主要因素。在现有的负荷侧强迫功率振荡机理的基础上,将冲击性负荷傅里叶分解为若干正弦波的叠加,通过模态法对单机无穷大系统和多机系统分别进行了分析,得出冲击性负荷引发的强迫振荡幅值比正弦扰动负荷更大的结论,并通过单机无穷大系统和IEEE 9节点系统算例进行仿真验证。

The problem of power grid forced oscillation is becoming more and more serious, while the research on forced oscillation caused by load-side is not deep enough. The theoretical derivation of the forced power oscillation mechanism caused by the non-sinusoidal continuous periodic load disturbance is improved, the differences of forced oscillations caused by the impulsive load disturbance and the sinusoidal load disturbance are compared, and the main influencing factors on the amplitude of forced oscillation are analyzed. Based on the existing load-side forced oscillation mechanism, the impulsive load is decomposed into the superposition of several sine waves by Fourier decomposition, and the modal method is used to analyze the single-machine infinite-bus system and the multi-machine system respectively, obtaining the conclusion that the amplitude of forced oscillation caused by the impulsive load disturbance is larger than that of the sinusoidal load disturbance, which is verified by the simulations of single-machine infinite-bus system and IEEE 9-bus system.