Frequency Dynamic Characteristic Analysis And Frequency Regulation Strategy Research Of DFIG

The development and utilization of renewable energy power generation technology is an important way to solve environmental problems and improve the energy structure of the system.Driven by the important energy strategic goal of "carbon peaking and carbon neutralization",the new energy power generation technology represented by wind power generation has developed particularly rapidly.Wind power generation equipment is networked through power electronic converters and does not respond to system frequency changes.The large-scale development of wind power generation will lead to the decline of power system frequency stability.Therefore,analyzing the frequency response characteristics of wind turbine groups and putting forward the frequency regulation control strategy is an urgent problem to be solved for the sustainable and large-scale development of wind power generation.This paper focuses on the frequency response characteristics of doubly fed wind turbine group,analyzes the dynamic coordination mechanism of DFIG group based on inertia response,and puts forward the primary frequency regulation control strategy of wind farm.The main work of this paper is as follows:In the research of power generation equipment in large-scale wind power interconnection system,the mathematical model and control strategy of DFIG are studied,and the time-domain simulation model of 2MW DFIG is established based on typical parameters;The speed regulation system model of synchronous generator set is established,and the inertia response of synchronous generator set and the reasons for its frequency modulation ability are discussed,which provides an analogy guiding idea for the subsequent study of the inertia characteristics of doubly fed synchronous generator set and the frequency regulation strategy,and establishes a wind power networking system example to verify the correctness of the model.In the research of dynamic coordination mechanism of DFIG group,the inertia expression of DFIG is deduced according to the frequency response model of DFIG,and the influence of PLL control parameters on the inertia characteristics of DFIG is analyzed.Combined with the parallel structure of DFIGs in the actual wind farm,the distribution law of unbalanced power among multiple DFIGs is analyzed,and the unbalanced power distribution coefficient of each unit in the field is deduced.The effectiveness of the theoretical analysis is verified based on time-domain simulation,which provides a guiding idea for the study of the frequency response characteristics of other forms of new energy generation networking systems.In the research of primary frequency regulation control strategy of DFIG,based on the primary frequency regulation control strategy of DFIG under all wind conditions,in order to solve the problems of unbalanced utilization of frequency regulation resources and difficulty in setting frequency regulation coefficient caused by the independent participation of units in primary frequency regulation the primary frequency regulation control system of wind farm is established based on the actual wind farm networking structure,According to the frequency deviation of the grid point,the unbalanced power required by the wind farm is calculated,and the unbalanced power is reasonably distributed to each unit for consumption according to the equal adjustable capacity proportion mode,so as to realize the primary frequency regulation of the wind farm participating in the system;The effectiveness of the proposed strategy is verified by time-domain simulation,which provides a new idea for new energy stations to participate in the research of system frequency modulation strategy.