1.College of Electrical Information Engineering,Changsha University of Science and Technology;2.State Grid Qinghai Electric Power Company Xining Power Supply Company
The boundary fluctuation of the actual power grid will cause low-frequency oscillation, and the oscillation of some lines under the main oscillation path is severe, which seriously affects the safe and stable operation of the power grid. Therefore, this paper studies the identification method of the main oscillation path under the boundary disturbance of the power grid. By comparing the similarities between power system and elasticity system, the power grid is mapped into elasticity network, and the dynamic model of elasticity is constructed to analyze the low-frequency oscillation of power grid from the perspective of mechanics. According to the energy conversion mechanism of forced vibration, the energy conversion characteristics of power system under power oscillation are analyzed. Combined with the interaction and distribution characteristics of network energy, the path oscillation index is established, and an identification method of main oscillation path is proposed. The simulation results show that the dynamic mapping between power system and elastic system is reasonable and the identification method of main oscillation path is effective. The conclusion of this paper is helpful to understand the physical process of low-frequency oscillation in power system, and has reference value to carry out the research of related measures to suppress oscillation.