Active Power-Frequency Oscillation Suppression Strategy for Parallel VSG Grid-Connected Power System

Virtual synchronous generator (VSG) has the problem of active power-frequency oscillation while providing inertia and damping for the system, especially in the parallel VSG system. Therefore, an oscillation suppress-ion strategy based on feedback-feedforward compound control (FFCC) is proposed. The output electromagnetic power feedback compensation and angular frequency feedforward compensation terms are constructed through first-order inertia and differential links, which effectively reduce the active power-frequency oscillation of the parallel VSG system without affecting the steady-state characteristics of the system. According to Lyapunov stability theory, the stability analysis is carried out, and the relevant parameters are designed. Finally, the simulation verifies the effectiveness and superiority of the proposed strategy to eliminate the parallel VSG grid-connected active power-frequency oscillation under the two-step disturbances of active power instruction and network frequency.