A Generic Power Compensation Control for Grid Forming Virtual Synchronous Generator With Damping Correction Loop

Insufficient damping and inertia are the one of the most tough challenges in the grid-connected power system with high penetration of renewable energy resources. Damping correction loop of virtual synchronous generator (VSG) connected to weak damping and high R/X ratio condition is introduced to solve the issues. First, the scheme of the proposed control is implemented in various system operating conditions, and the small-signal model of the proposed control is established. Subsequently, the influence of the damping correction loop on small-signal stability is demonstrated by Bode diagram analysis, and the interaction between reshaped VSG control and power compensation capacity is clarified in three aspects of damping, inertia and synchronization. Furthermore, the optimal design of additional damping and inertia support is provided to suppress the subsynchronous frequency fluctuation of the system, the proposed control method can be easily implemented by directly inserting it into active power control loop of VSG. Finally, the efficiency of the damping correction loop is verified by experiments, the results indicate that 70% reduction of maximum frequency deviation with the proposed control under 20% active power reference step.