Research of the Mechanism of Low Frequency Oscillation Based on Dynamic Damping Effect

Abstract

-For now, there are some low frequency oscillations in the power system which feature low frequency oscillation with positive damping and cannot be explained by traditional low frequency oscillation mechanisms. Concerning this issue, the dynamic damping effect is put forward on the basis of the power-angle curve and the study of damping torque in this article. That is, in the process of oscillation, damping will dynamically change and will be less than that of the stable operating point especially when the angle of the stable operating point and the oscillation amplitude are large. In a situation with weak damping, the damping may turn negative when the oscillation amplitude increases to a certain extent, which may result in an amplitude-increasing oscillation. Finally, the simulation of the two-machine two-area system verifies the arguments in this paper which may provide new ideas for the analysis and control of some unclear low frequency phenomena.

Research and simulation analysis of crack failure mechanism of conductor spacer bar in ±800 kV converter station

“…Spacer bars, as an indispensable tool in ultrahigh voltage transmission lines, are installed on multi-split high-voltage transmission lines to ensure that the split wires can maintain the same distance between the wires under the influence of wind, ice covering of wires, dance and short circuit current, etc., to meet the electrical performance, reduce the surface potential gradient, and avoid mutual whipping between sub-wires. It also has the effect of suppressing wind vibration and sub-range oscillation [1][2][3][4].…”