Research on Adaptive Control Strategies for Virtual Synchronous Generator Inertia and Damping Parameters Based on Active Power Deviation

Renewable energy systems exhibit inherent low inertia and weak damping. Their large-scale grid integration via grid-forming inverters increases susceptibility to disturbances, causing dangerous power/frequency oscillations beyond stability limits. To address the insufficient ability of conventional VSG (virtual synchronous generator) with constant inertia and damping coefficients to suppress output power and frequency fluctuations during transient disturbances, this study analyzes the influence of inertia and damping coefficients on VSG output power and frequency characteristics in transient processes. Furthermore, it determines the variations of inertia and damping at different stages of the disturbance. First, the deviation and rate of change of the VSG output angular frequency are simultaneously considered to achieve frequency fluctuation suppression. To avoid unnecessary noise interference caused by derivative operations in adaptive control, the angular frequency derivative term in the original control loop is replaced with the power deviation. This substitution not only simplifies the control structure but also improves the dynamic waveform of frequency regulation. Finally, simulations verify the effectiveness of the proposed adaptive control strategy in suppressing active power and frequency fluctuations under disturbances.