Utilizing the potential frequency regulation capability of flexible HVDC systems can effectively support grid frequency stability. However

conventional frequency regulation methods reduce the tracking speed of reference power changes because of increased virtual inertia

and decrease voltage control stability margins

thereby weakening the system’s frequency support capability. To address this issue

a parameter decoupled virtual synchronous generator (VSG) strategy based on voltage control is proposed. First

the auxiliary frequency control of the converter station and conventional VSG control method are analyzed. A DC bus voltage is introduced

and a droop-based PI controller is used to regulate voltage deviations. Then

an improved active power loop (APL) control is proposed. It incorporates a low-pass filter and a feedforward loop to eliminate the inherent oscillation poles of the VSG

thereby decoupling the reference power tracking speed of the APL from the virtual inertia support capability provided by the VSG. Finally

the proposed strategy is simulated and validated using Matlab/Simulink. The results show that the proposed strategy enables independent control of virtual inertia and reference power tracking through two separate parameters

rendering the control approach more flexible. Additionally

it effectively enhances the frequency support capability of the converter station while ensuring excellent voltage control performance.