With the construction and incorporation of large-scale wind farms，the contradiction between the source（wind generators）and the grid is highlighted increasingly.Due to grid constraints，some installed wind generators cannot be incorporated into grids，and the wind curtailment happens in some commissioning wind generators.This grid can be defined asa transmission constrained grid with surplus wind generators”.For a grid dispatcher，only the specific capacity of wind generators can be dispatched.Even if the grid transmission space used to transmit wind power is known，due to the fluctuation characteristics of wind power，it is difficult to determine how much specific capacity of wind generators is suitable for sufficiently utilizing this space.This paper proposes a method to coordinate the source and the grid by the fluctuation characteristic analysis of wind power.The method can maximize the grid transmission space for wind power to improve the utilization of grids and wind energy while ensuring the grid security.