In the context of transportation-energy integration, the integration of massive power electronic devices and the presence of long transmission lines in transportation microgrids weaken the interconnection between the grid and generators. This leads to an increase in the equivalent impedance of the grid, giving rise to weak grid characteristics. For grid-connected inverters with weak interconnections, phase-locked loops (PLLs) and current control loops introduce wide-frequency negative damping, posing risks of wide-area instability. Traditional capacitor current feedback active damping stabilizes grids in a certain variation range but fails to adapt to large grid parameter variations. Therefore, to address the scenario of wide-range grid impedance variations, this paper proposes a targeted active damper based grid-connected stability enhancement method, adaptively adjusting active damper virtual impedance according to grid high-frequency resonant components to improve wide-area frequency stability. PLECS based simulation models verify the method’s correctness and effectiveness, demonstrating its ability to ensure renewable energy grid-connected stability under wide-range impedance variations, enhance transportation microgrid operational robustness and reliability, and exhibit engineering universality and application prospects.