Research On Coordinated Control Of Wind And Energy Storage System In Respect Of Large-scale Wind Power Intergration Into Grid

Along with the rapid development of wind power, wind power penetration gradually increases in power system, which impacts the stable operation of power system. This requires that wind turbines must have certain characteristics to reduce the impact of wind turbines intergration into grid on power system. This paper will address the voltage ride through problem and frequency regulation problem under review. By analyzing the system characteristics, with the aid of energy storage system of the flexible control function, control strategy is proposed in this paper to improve the wind power intergration into grid feature. Finally simulation verifies the correctness of the proposed control strategy. Specific completed work content is as follows:Firstly, the structure of wind turbine is analysed. The modelings of wind turbine, generator, grid side converter, and rotor side converter have been researched. The vector control and maximum power tracking control have been analysed in detail. Finally simulation verifies the correctness of the model and provides theoretical basis for subsequent analysis.In terms of voltage ride through, a coordinate control strategy, which uses super capacitor(SC) based dynamic voltage restorer(DVR), is proposed to improve the voltage ride through of doubly-fed induction generators(DFIG). The active power is absorbed by DVR and DFIG through the proportional distribution of coordinated control strategy.Making full use of the compensation ability of DVR and wind turbine rotor rotational kinetic energy to ensure the grid voltage stability is constant and the wind turbines can be sustained parallel operation. The validity of the proposed coordinate control strategy is verified by the simulation results.Numerical example results show that the coordinated control strategy canreduce the capacity and power of the dynamic voltage restorer. It has great significance for engineering applications.Finally, in the aspect of frequency adjustment, the modelings of the conventional units, wind turbines, energy storage system, wind store coordinated control system and containing the wind store coordination of system frequency characteristic of the power system are researched.Short-term frequency control strategy of wind turbine is studied. Aiming at the existing problem of wind turbines to participate in the system of frequency adjustment, coordinated control strategy of the energy storage with wind frequency adjustment is put forward. Finally simulation verifies the effectiveness of the proposed control strategy and it can reduce the wind turbine power output, accelerate the rotor speed recovery, and prevent the secondary frequency drop.