Coordinated Control of Adaptive Damping and Additional Torque for Transient Stability Improvement of Virtual Synchronous Generator

The usage of the virtual synchronous generator (VSG) technology in renewable power sources brings the power angle stability problem similar to that of traditional SGs. In this paper, the influence of the damping coefficient and unbalanced torque on the transient stability of a multi-VSG system is analyzed, and an improved control strategy considering adaptive damping and additional torque is proposed. The theoretical model is constructed, and the frequency difference is used for the adjustment of the damping value and the torque magnitude, which contributes to bringing a favorable regulation response and realizes the stability improvement. Furthermore, a laboratory-class multi-VSG system model is built in MATLAB platform, and comparative simulations are implemented. The simulation results manifest that the proposed method can availably suppress the variation of the rotor angle of the VSGs, and the system frequency in the fault transient process is visibly stabilized.