Research On Unit-level Frequency Regulation Characteristics And Field-level Frequency Regulation Strategy Of Doubly-fed Wind Far

With the proposal of the goal of "carbon neutrality" in the national new energy plan,renewable energy has become an inevitable choice for the development of green economy.Among them,the development of wind energy is relatively rapid.However,the randomness and volatility brought by large-scale wind power grid connection will have an adverse impact on the stability of power grid system.Therefore,the research on wind power participating in power grid frequency modulation from different levels has become an inevitable trend to ensure the safe and stable operation of the system.Aiming at the Doubly-Fed Induction Generator turbine participating in the primary adjustment of power grid frequency,this paper studies the frequency modulation characteristics of the unit layer,the coordinated control and optimization of the units in the field layerIn view of this situation,this paper studies the participation of DFIG turbine in power grid primary frequency regulation.Firstly,according to the basic operation characteristics of doubly fed wind turbine and primary frequency regulation control strategy,the mathematical models of DFIG turbine and diesel generator system are established.On this basis,in order to study the influence of virtual inertia coefficient and droop control coefficient on the frequency of fan parallel point,the dynamic theory analysis under high-frequency disturbance and low-frequency disturbance is carried out by changing different loads.It is verified by simulation in Matlab / Simulink simulation platform.Then,combined with the frequency modulation strategies such as virtual inertia control and droop control of DFIG turbine,a wind farm power allocation strategy based on rule queuing method is proposed.The strategy takes the predicted wind speed as the standard,groups the units in the site,and uses the comprehensive inertial control to calculate the power to be distributed on the exit floor.Then compare the power to be distributed with the lifting power capacity value of the wind turbine.The real-time power allocation is carried out according to the rule queuing method.Respond to the change of dot frequency.Finally,the frequency modulation model of DFIG farm is built in the simulation platform.The effectiveness of coordinated control among units in the layer of doubly fed wind farm is verified.Based on the above research,in order to realize the efficient and intelligent frequency modulation control of doubly fed wind farm layer,the existing regular queuing method is optimized.In this optimization measure,the simulation results of fan power,pitch angle and predicted wind speed obtained by the allocation strategy of regular queuing method are used to fit the polynomial.Taking the relationship as a bridge,the objective function variable is connected with the constraint condition variable,and then combined with the constraint condition,the objective function is solved and the power is allocated.The effectiveness of the method is verified by comparing with the frequency modulation effect of the regular queuing method.