Research On Power Fluctuation Suppression Of Double-fed Wind Turbines In Flexible DC Transmission System

Wind power does not have the unique relative stability of traditional fossil fuel power generation.The wind speed fluctuation and uncertainty will cause the wind turbine output power to fluctuate,which will affect the stable operation of the power system.This paper aims to stabilize the wind power output power fluctuation and reduce the adverse impact of wind power fluctuation on the power system.A new flexible DC transmission doubly-fed wind turbine platform is proposed,which uses the energy storage system for power control.Mainly from the following aspects:Firstly,the research background and significance of the subject are expounded.The research status of wind power fluctuation and energy storage power converter is analyzed.A new topology based on flexible DC transmission doubly-fed wind power generation system is proposed.The new topology is compared with the traditional one.The advantages of topology are analyzed.The configuration of energy storage equipment in wind farms is compared and analyzed.A new energy storage configuration method suitable for new topologies is proposed.Secondly,based on the specific requirements of wind power fluctuation,the mathematical model of energy storage system is established.The wind power power fluctuation control strategy based on the average wind speed principle is designed.The energy storage capacity calculation method that meets the energy requirements of the smoothing process is given.The relationship between energy storage capacity and environmental factors and fan characteristics is briefly analyzed,which provides reference for the configuration of wind farm energy storage system.On the MATLAB/Simulink platform,the energy storage system operation control simulation platform was built,and the effectiveness of the designed control method was verified by simulation.Thirdly,the mathematical model of energy storage power converter is established,and the performance characteristics and technical indexes of energy storage power converter are given.The topology structure of energy storage power converter is given.Based on this,the hardware circuit of energy storage power converter is developed.Design and software design(including primary and secondary).Finally,an experimental platform based on the new topology of flexible DC transmission doubly-fed wind power generation system is built,and the designed control method is experimentally verified.The results show that the control method proposed in this paper can effectively suppress wind power fluctuations.