To improve the synchronous stability of the power system integrated with wind generators， a wind power system energy function is proposed based on the energy conservation law. Then a stability control strategy based on the energy function is introduced. The impacts of double fed induction generator（DFIG） operation limits on the control are also discussed. In the variable speed operation mode， the wind generators eliminate the unbalancing energy to restrain the system oscillations. A testing system including a DFIG-based wind farm is realized using DIgSILENT/Power Factory to demonstrate the effectiveness of this strategy. The simulation results show that， in different system operation modes， the control strategy is effective in improving the power system synchronous stability without deteriorating the system voltage stability.