Abstract: The integration of renewable energy has become a defining feature of modern power systems, spurring significant research interest in grid-forming converters based on Virtual Synchronous Generator (VSG) control. To address control challenges in grid-connected photovoltaic-storage systems, this study proposes an adaptive control methodology that incorporates DC-link capacitor voltage stabilization. The approach accounts for multiple interacting factors influencing virtual rotational inertia—including VSG power-angle characteristics, rotor angular frequency dynamics, and DC-bus voltage fluctuations—establishing a dynamically mapped relationship between voltage deviation and virtual inertia. Stability is analytically guaranteed by means of Routh-Hurwitz criterion, while optimal parameter tuning is achieved to balance dynamic response and stability margins. Simulation results demonstrate superior performance compared to conventional adaptive control methods, yielding an 8.49% reduction in voltage fluctuations and improved power-frequency response characteristics. The proposed strategy simultaneously maintains DC-link voltage stability and enhances dynamic response, providing critical technical support for stable operation of power systems with high renewable penetration.