Instantaneous Energy Dynamics of Wideband Oscillations in Inverter-Dominated Power Systems Based on Port-Hamiltonian Energy Model

Power systems dominated by power electronic inverters exhibit a high degree of operational flexibility; however, under certain operating conditions, they are susceptible to multi-mode wideband oscillations in the frequency range of several hertz to several tens of hertz. The transient energy evolution mechanisms associated with these oscillations have not yet been fully elucidated. To address this challenge, this paper proposes a port-Hamiltonian energybased modeling and analysis framework for inverter-dominated power systems, in which system dynamics are formulated in a Hamiltonian energy representation to reveal the propagation, accumulation, and dissipation mechanisms of wideband oscillations. Firstly, a port-Hamiltonian energy model is established to enable unified modeling and energy decomposition of key electrical and control subsystems, while systematically characterizing the dynamic energy coupling among these subsystems. Subsequently, a real-time quantitative analysis method for wideband oscillation energy is developed. Based on modal energy interaction characteristics and parametric energy sensitivity, an oscillation source localization criterion is formulated to identify oscillation energy injection paths and dominant control loops.