Synergistic adaptive control of virtual inertia and damping coefficient in virtual synchronous generators for standalone microgrid applications

Abstract

The current control methods for virtual synchronous generators (VSG) in regulating inverter frequency in standalone microgrids at border posts and remote mountainous regions remain suboptimal. This study introduces a small-signal VSG model to elucidate the intrinsic dynamics of the virtual inertia and damping coefficient, along with their coupled interrelationship. A novel VSG control approach is proposed, featuring synergistic adaptive regulation of both virtual inertia and damping coefficient. This approach is designed to optimize the interaction of the virtual inertia and damping coefficient with the frequency difference and rate of frequency variation, within a predefined operational range. Additionally, it adaptively modulates these parameters to mitigate further frequency reductions, taking into account the frequency difference and active power when deviations occur outside the predefined range. The experiments demonstrate that this approach effectively moderates the rate of frequency change, diminishes frequency departure velocity for approximately 4 times the original during disturbances, expedites frequency stabilization post-disturbance, the stabilization time is reduced by at least half of the original and prevents excessive frequency deviations. The implementation of this method significantly enhances the response speed and accuracy of frequency control in standalone microgrids, contributing to improved overall system stability.

Keywords

• damping coefficient
• standalone microgrid
• synergetic adaptive control
• virtual inertia