During low voltage ride-through

doubly-fed wind farms can compensate for the reactive power demand of the grid

providing voltage support. However

current voltage sag assessments fail to consider this effect

leading to inaccurate evaluation results. To address this issue

this paper proposes a voltage sag assessment method for grids with high wind power penetration based on dynamic equivalent clustering. First

to better illustrate the impact of each unit's crowbar status on the dynamic reactive voltage support capability of wind farms

this study proposes a rotor current calculation method considering the reactive power priority control strategy of doubly-fed induction generators during grid faults. The method accurately determines the crowbar protection operation status. Then

to reflect the interactive influence between the dynamic changes in crowbar status and the voltage sag magnitude at nodes

this paper carries out a dynamic equivalent method for wind farms by iterative clustering

taking into account the mutual influences among wind farms. Finally

a full grid fault simulation is conducted to obtain the voltage sag assessment results. The simulation and validation results demonstrate that the proposed method effectively evaluates the impact of wind farms' dynamic voltage support on the depth of voltage sags under various fault conditions. It provides an accurate and efficient assessment of voltage sags for high levels of wind power integration into the grid.