当系统频率增大时，频率控制环节作用，使风力机转速增加，储存转子动能，降

When the system frequency increases, the frequency control link acts to increase the speed of the wind turbine, store the rotor kinetic energy, and reduce the active output; when the system frequency decreases, the frequency control link reduces the wind turbine speed, releases the stored rotor kinetic energy, and inputs it to the system A certain amount of active power thus realizes the function of adjusting the system frequency. Since the doubly-fed wind turbine realizes variable speed operation, its rotor speed has a wide operating range. It can be seen from Equation 2-15 that the change of the rotor speed of the wind turbine generator can provide approximately 66% of the rotor kinetic energy. It is precisely because of this characteristic that the number of wind turbines in the power grid will affect the moment of inertia of the entire system, and its contribution to the moment of inertia of the entire system cannot be ignored.

When the frequency of the system increases, the frequency control link, so that the wind turbine speed increases, the storage of rotor momentum, reduce the active output, when the system frequency decreases, the frequency control link makes the wind turbine speed decrease, release the stored rotor momentum, input a certain amount of active power to the system, so the role of regulating the system frequency is realized. Since the double-feed wind turbine has achieved variable speed operation, its rot speed is very wide, and the change of rotter speed of the wind turbine unit can provide about 66% rone momentum as can be known by the type 2-15. It is because of this characteristic that the number of stroke motors in the power grid affects the rotation inertia of the whole system, and its contribution to the rotation inertia of the whole system cannot be ignored.

When the system frequency increases, the frequency control link will increase the speed of the wind turbine, store the kinetic energy of the rotor and reduce the active power output; when the system frequency decreases, the frequency control link will reduce the speed of the wind turbine, release the stored kinetic energy of the rotor and input a certain amount of active power to the system, so as to realize the function of adjusting the system frequency. Due to the variable speed operation of the doubly fed wind turbine, the rotor speed range is very large. From equation 2-15, the rotor speed variation of the wind turbine can provide about 66% of the rotor kinetic energy. Because of this characteristic, the number of wind turbines in power grid will affect the moment of inertia of the whole system, and its contribution to the moment of inertia of the whole system can not be ignored.<br>