Energy Storage Assists Wind Turbines to Participate in Grid Frequency Regulation Control Strategy Research

Wind turbine generators are connected to power grid via power electronic equipments, so the kinetic energy of the rotor is decoupled from system frequency and cannot provide inertial support for grid frequency changes. Along with the increase of the proportion of wind power in power grid, system frequency stability will be severely challenged. For this reason, a variable coefficient integrated inertial control was proposed to make wind turbine enable to flexibly regulate its power output according to the magnitude of frequency disturbance. On this basis, combining with pitch angle deloading control and by means of the segment handling of wind speed, the wind turbine could participate in grid frequency modulation more effectively and targeted. In addition, in order to further optimize the frequency regulation performance, energy storage devices were added in wind power grid-connection system. The inertia of wind power energy storage system was analyzed in detail, and a joint frequency modulation control strategy for wind power energy storage system was proposed, and in allusion to the problem that how to distribute the output of wind power energy storage within medium- and high- wind speed range, a fuzzy logic control strategy was adopted to realtime regulating the output coefficient of energy storage system. Finally, the frequency regulation storage for the proposed wind power energy storage was verified by simulation. Simulation results show that using the proposed method the effect of frequency regulation by wind power units can be effectively improved, so it is beneficial to ensure the frequency stability under high proportion grid connection of wind power generation.