Research On Coordination Strategy Of Primary Frequency Control Between Wind Power Plant And Conventional Power Plant

With the strategic goal of building a new power system with new energy as the main body proposed in China,the participation of wind power in primary frequency control has gradually become an inevitable trend and urgent requirement to ensure the stability of the frequency of high-proportion new energy power systems.The fluctuation of wind power leads to the fluctuation of wind power frequency regulation capability.Quantitative assessment of wind power frequency regulation capabilities and research on coordinated control of primary frequency modulation between wind power and conventional power are urgently needed.Based on direct drive wind turbine,this paper studies the evaluation method of frequency regulation capability,the frequency regulation control strategy of wind power,and the coordinated control of the combined primary frequency regulation of wind power plant and conventional power plant.According to operating principle of direct drive wind turbine,the mathematical model of direct drive wind turbine was built,including the ontology model,steady-state control model,fault ride through control model and frequency regulation control model.The wind turbine model is built on the simulation platform.According to the modeling guide for wind turbine electrical simulation model,the effectiveness of the simulation model is verified by the measured data of low voltage ride through and primary frequency regulation.The results show that the deviation can meet the requirements,and the simulation model can reflect the dynamic characteristics of the actual wind turbine well.The mechanism of wind turbine participating in system frequency regulation is analyzed,and the frequency response stage of the grid is studied.The mechanism of wind turbine integrated inertia control and primary frequency control participating in the system frequency regulation is studied and the frequency response process of the electric grid of high wind power penetration after frequency disturbance is analyzed.A simplified frequency response model of wind power system is established,and the factors that affect the frequency response characteristics of wind power frequency control system are analyzed.Ultimately,considering the dead zone of primary frequency control,the frequency response stage of the system is divided according to the system frequency response process of each part of the role,and the frequency response process of the grid key evaluation indicators of frequency response are analyzed.The quantitative evaluation of frequency control capability of over-speed wind turbines is studied,and a comprehensive control strategy of frequency control for wind turbines with accurate consideration of frequency regulation capability is proposed.Considering the rotor speed limit of wind turbine,the frequency control capacity of wind turbine to different types of frequency disturbances under different operating conditions is quantitatively evaluated.Proposed a comprehensive control strategy of wind turbine frequency support combined with virtual inertia control and primary frequency regulation control based on the quantitative evaluation results of frequency regulation capability.The effectiveness of the proposed strategy is verified by simulation.Aiming at the problems that make the coordination strategy of primary frequency regulation between wind power and traditional synchronous generator considering system frequency stability.Through the quantitative evaluation of the wind farm’s frequency regulation capability,and then proposes a coordinated primary frequency control strategy of wind power and conventional power: according to the wind power frequency regulation ability evaluation results,and the active power output of the system,the frequency regulation capability state of the wind power in the grid is determined,and the frequency regulation parameters of synchronous units are set according to the frequency regulation capability state of the wind power.The simulation results indicate that the proposed method can give full play to the advantages and capability of wind power frequency regulation technology on the premise of ensuring power system frequency stability.