Research on the method of frequency modulation rotor kinetic energy of DFIG with speed difference compensation

With the increasing proportion of wind power generation in the power grid, wind turbines should not only capture the maximum wind energy, but also have the ability of frequency regulation. Doubly fed asynchronous wind turbine (DFIG) is the main type of large wind farms at present, According to the characteristics of DFIG, starting from the rotor kinetic energy, by controlling the load shedding operation mode of DFIG, coordinating the relationship between the rotating kinetic energy and load shedding power of the wind turbine, controlling the release process of rotor energy, making full use of the rotating kinetic energy of the rotor, and improving the capacity of frequency modulation in wind turbine grid. On the basis of integrated inertia control, this paper proposes for the first time that the rotor kinetic energy can be better released by adding a rotor speed difference compensation loop control module, so that DFIG can further make full use of the rotational kinetic energy stored in the rotor to provide short-term power support for the power grid, realize the normal operation, reserve part of the power, and taking part in the frequency regulation in the power grid actively. The simulation results show that the control strategy with rotor speed compensation loop is obviously superior to the integrated inertia control in the primary frequency regulation characteristics of the power grid, improves the frequency regulation ability, and can effectively reduce the impact of large-scale wind turbine grid connection on the frequency stability of the power system.