Research On Frequency Control Strategy Of Wind Turbine Based On Adaptive Coefficient

In recent years,in order to alleviate the energy crisis and environmental problems caused by over-exploitation of fossil energy,renewable energy resources generation technology has gradually become an important research area.As an important part of renewable resources,wind power generation is widely studied in the industry.Due to the randomness and fluctuation of wind energy in nature,the output power of wind farms is unstable.At the same time,large-scale wind farms are constantly increasing.When connected to the power grid,it will bring some influences to safety and stability of the power system.Therefore,the power control of wind power generation and the ability to participate in grid frequency regulation have become the main research content.This paper studies the control strategy of wind Power participating in the primary frequency regulation of the power system and proposes a method based on power reserve control and adaptive inertial control.The main work is as follows:Firstly,the background and significance of wind power participation in frequency regulation are introduced.The research status of wind power participation in frequency regulation is analyzed and introduced in detail.The differences between various control strategies are compared,and the advantages and disadvantages of different control methods are explained.The basic model of wind speed,the basic structure and basic principle of wind turbines are studied;the basic composition of DFIG is introduced in detail and basic principles of the rotor-side converter and the stator-side converter of a DFIG are analyzed.The control strategy of the inverter is introduced;the maximum power point tracking coltrol of DFIG is introduced;the power characteristics of DFIG at different operating stages are analyzed.For the power reserve control,the basic principles of the overspeed control and the pitch angle are given respectively,and the applicable ranges of the overspeed control and the pitch angle are explained.The wind speed is divided into three di:fferent regions:low-speed region,medium-speed region,and high-speed region.The power reserve control in each region is given and the basic rule for wind speed division is given.A simulation model of the unit was built in MATLAB/Simulink to verify the effect of the wind turbine power reserve control.The simulations of different power reserve margins were performed at low,medium,high and random wind speeds.The experimental results of the maximum power tracking mode and the power reserve mode are used to verify the effectiveness of power reserve control.A control coefficient adaptive method based on virtual inertia control is proposed.The inertia coefficient and droop coefficient are adjusted in real time according to the current operating conditions of the unit,so that the unit can effectively participate in the frequency regulation of the system.In order to verify the effectiveness of the method proposed in this paper,a wind farm power generation system model was built on the MATLAB/Simulink simulation platform.Under different wind speed conditions,three different control strategies were compared,that is,no additional coefficient control strategy,fixed coefficient control strategy and the adaptive coe:fficient control strategy proposed in this paper.Finally,the simulation results verified the effectiveness of the adaptive coefficient control strategy for primary frequency regulation.