In recent years， the renewable energy in Northwest Power Grid has experienced fast development， and the HVDC has been sending increasing power to the rest of the country. Due to the fact that the renewable generation units do not have the ability to participate in the primary frequency regulation， the frequency control of large power grid has become an increasingly prominent predicament. It is therefore in desperate need to have renewable generation units participating in the frequency regulation. This paper introduces the typical schemes of the wind farms participating in the system frequency control as tested in the Northwest Power Grid. According to the field tests and the 2016 Northwest Power Grid frequency characteristics tests， this is the first time in our country to conduct a systematic actual measurement and analysis of the fast frequency response capacity of wind farms. The results show that wind farms are able to participate in the fast frequency response of power grid， and they have similar response capability compared to conventional generators. Therefore， it is very promising to implement the control scheme.