Research On Wind Power Participating In Primary Frequency Control Strategy Based On Improved Load Shedding Control Mode And Priority Parameters

Due to the characteristics of randomness and volatility of wind power,the problem of system frequency stability is becoming the increasingly serious.In order to participate in the primary frequency regulation of the system and optimize the frequency response of the system more effective,this paper studies the control strategy when the DFIG and wind farm participate in the system frequency regulation.The main contents are as follows:First of all,this thesis studies the specific composition of DFIG and the mathematical model of it,this paper analyzes the operating characteristics of DFIG in different working intervals;and studies and discusses two common load reduction methods for wind turbines,and formulates DFIG in different wind conditions Under the load shedding control strategy.Secondly,in order to reduce the influence of the hysteresis and delay of the pitch angle control on the output power of the DFIG during load shedding,this paper ameliorate the original rotor overspeed-pitch load shedding control strategy which is based on Matlab/Simulink,and use the simulation software builds a DFIG model,simulates the DFIG load reduction process under different wind conditions.We analyzes its steady-state and dynamic processes.The results show that the improved load reduction control strategy can optimize DFIG load reduction well The power output process at the time reduces the impact of the pitch angle control's own characteristics on the load shedding process.Then,this thesis analyzes the function realization process of each system in the DFIG frequency modulation control system in detail,studies the basic principle of DFIG participating in system frequency modulation,and formulates the control strategy when the DFIG is disturbed by the system frequency under different wind conditions based on the power tracking method.And use Matlab/Simulink software to simulate the system frequency decline and rise,the simulation results show that DFIG based on power tracking control can achieve the corresponding power support for frequency fluctuations.Finally,in order to optimize the inertial response of the wind farm and reduce the frequency of the second drop when participating in the system frequency modulation,this paper proposes a strategy of input and exit frequency regulation based on the priority parameters of the wind turbine,by calculating the priority parameters of each wind turbine in the wind power plant to determine whether the wind turbine is involved in frequency modulation or exit and the corresponding sequence,which is based on Matlab/Simulink software,then we built a wind farm grid connection model for simulation.The simulation results show that the proposed wind farm based on the priority parameter input and exit frequency modulation strategy can be Effectively optimize the inertial response of the wind farm when participating in the system frequency modulation,and reduce the secondary drop value of the frequency when the wind turbine exits the system frequency modulation.