Small-signal stability assessment and damping control of grid-forming (GFM) controllers in grid-tied are limited to specific frequency bands, lacking comprehensive verification of wideband stability improvement. This paper aims to reveal the impact of different damping control methods from a wideband stability perspective and provide an integrated solution. An impedance model considering coupled control loops is developed in the dq frame to extract dominant oscillation modes in both low and high-frequency bands. Then, candidate damping control methods such as virtual resistor and feedforward compensation are compared to reveal their different damping impacts on wideband oscillation modes and possible side effects. Based on the assessment results, an appropriate solution is selected for wideband stability improvement. The findings of this work are verified under experimental conditions.
