Because mostly used variable speed wind turbines based on doubly fed induction generator (DFIG) do not provide with transient voltage support capability under fault conditions, the security and stability of grid is influenced by wind farms integration in the case of severe short circuit fault contingency occurred on the grid side. The modified power converter controller model with transient voltage support capability and pitch control model used for post-fault stability control are implemented in DIgSILENT/PowerFactory. The models validation and the contribution to transient voltage stability enhancement are verified by power system simulation containing large wind farms. From simulation results, it can be illustrated that modified power converter controller with transient voltage support capability can provide dynamic reactive power to support grid voltage recovery and the modified pitch control model can reduce mechanical power , preventing wind turbines from over-speeding and also providing more reactive power generation stability for the power converter controller in the duration of power system large disturbance. The conclusion is presented that the control strategy can effectively improve the transient voltage stability of the gird.