Investigation Of Power Oscillation Damping Based On Interventional Excitation Control

As the development of power system, the structure of power grid gets more and more complex. The problem of LFO becomes prominent increasingly. low frequency oscillation (LFO) becomes a serious threat to power system stability. As a result, the study of new method to damp LFO has practical significance. On this background, this paper studies a novel way to damp power oscillation using interventional excitation control method, which is aim to offer a new idea for damping LFO.At first, the phenomenon and harm of power system LFO are described in the paper. Then analysis methods and damping methods of LFO are summarized. After that paper also explains the necessity of developing new LFO damping methods.Secondly, both vector diagram method and phase plane method are used to explain the mechanism of LFO. Then the negative damping effect is discussed. After that, as a basis, eigenvalue analysis method of multimachine System is introduced. And the effect of operation modes on system eigenvalue is also discussed.Thirdly, the concept and characteristics of interventional excitation control method are descried. Then the detailed design steps of LFO damping method based on interventional excitation control is proposed. on the other hand, a lookup method to identify operation mode matching with control mode are also described in the paper.Finally, the detailed design method of PSS based on wide-area measurement system (WAMS) is introduced, including how to fix installation site, how to calculate the parameters of PSS with various input signals. The effects of PSS with various input signals on damping tie-line mode power oscillation are compared. From the time domain simulation, we find that the PSS with the most value participation factor input signal is the most effective one in damping power oscillation. On the other hand, the tie-line power oscillation curves show that interventional excitation control method can damp LFO better than the ordinary one, which helps to improve the dynamic stability of power system.