Analysis of dynamic energy characteristics of low frequency oscillation under different mechanisms in large power grid

Low-frequency oscillations are widely found in interconnected power grids all over the world, limiting the transmission capacity and threatening the safety of power grids. Therefore, it is necessary to study the mechanism and characteristics of low-frequency oscillations. This paper reveals the difference between the negative damping mechanism oscillation and the forced power oscillation in the energy change when the time-domain oscillation is similar, and summarizes the method of locating the disturbance source of the forced oscillation source through the characteristics of the branch energy distribution; researches the generalized forced oscillation of the power system triggered by the random disturbance, and verifies the applicability of the method of tracing and locating the source of the generalized forced oscillation; The oscillation mechanism of the generalized forced oscillation phenomenon caused by random disturbance in the power system is analyzed, and the concept of dynamic energy is constructed. The transformation law of dynamic energy is explored through simulation and comparative analysis and observation. • Difference in energy evolution: Revealed linear vs. exponential trends for forced and negative damping oscillations. • Quantitative localization: Proposed the Energy Slope Ratio (ESR) metric to objectively locate oscillation sources. • Generalized forced oscillation: Verified the method's effectiveness under broadband stochastic power disturbances. • Theoretical proof: Derived analytical expressions for potential energy increments to ensure method robustness. • Energy-based analysis: Constructed a dynamic energy framework to trace oscillation propagation in large power grids.