Grid-Connected Active Power and Frequency Response Strategy for Fractional-Order Virtual Synchronous Generators Based on Lead-Lag Correction
Fractional-order virtual synchronous generators (FOVSG) exhibit an inherent trade-off between active power transient response and inertia frequency response under active power command steps and grid frequency disturbances. This paper proposes a lead-lag correction FOVSG (LLC-FOVSG) strategy that introduces a lead-lag correction block into the rotor motion equation of the FOVSG. A small-signal model of the grid-connected LLC-FOVSG is constructed to enable systematic parameter tuning. The correction block reshapes the loop gain such that the active power response remains damped while the frequency response avoids overshoot. Simulation and hardware-in-the-loop tests on a 100 kV·A prototype compare the LLC-FOVSG against the conventional FOVSG. Results demonstrate that the LLC-FOVSG achieves superior simultaneous improvement in both active power and frequency dynamic responses, effectively resolving the long-standing conflict between power oscillation suppression and frequency overshoot mitigation in fractional-order virtual inertia control.