Abstract:
Virtual synchronous generator (VSG) not only introduces the second-order rotor motion equation of the synchronous machine to increase the equivalent inertia of the power system, but also introduces the oscillation characteristics of the synchronous generator, leading to dynamic stability issues such as active low-frequency oscillation. The introduction of a governor power system stabilizer (GPSS) can effectively suppress the low-frequency oscillation of VSG power, but its control effect in terms of overshoot and regulation time still needs to be improved. By establishing a small signal model of VSG and analyzing its stability from the perspective of pole configuration, it is revealed that the VSG control strategy based on GPSS has high overshoot and long adjustment time in power dynamic response. Thereby, referring to the GPSS control concept, a virtual synchronous generator control strategy based on additional feed-forward damping compensation with leading and lagging links is proposed. And it is theoretically analyzed and verified that the proposed control strategy can provide positive damping with higher degrees of adjustment freedom without affecting the steady-state characteristics of the system, effectively suppressing the power overshoot while improving the system's adjustment speed, thereby better suppressing low-frequency oscillation of active power. Finally, comparative simulation was conducted using MATLAB/Simulink, and the simulation results were consistent with the theoretical analysis results, proving the correctness and effectiveness of the proposed control strategy.