It is objective demand for the grid connected wind farms to take part in secondary frequency regulation and actively provide reserve capacity

and power-limited operation of wind farm is a necessary condition for wind farm to participate in frequency regulation. This paper quantitatively analyzes the influence of power-limited operational condition of wind farm on the index of secondary frequency regulation and maximum penetration power of wind power

assuming that it will be able to reduce the pressure of synchronous generator in reserve capacity and frequency regulation speed aspects as well as raise maximum penetration power of wind power. In order to study the dispatch problem of secondary spinning reserve under power-limited operation of wind farm

the reserve optimization and the dynamic equivalent model consisted of equivalent synchronous generator and wind turbine are established

which is solved by MATLAB/Simulink. The optimization and simulate results show that the wind farm working in power-limited state will increase the stability of power grid and reduce spinning reserve.