| Under the "dual carbon" vision,during the "14th Five-Year Plan" period,the scale of integration of wind power into the grid will reach new height.It is estimated that in 2030,the installed capacity of wind power is expected to reach 2.2 billion kilowatts.However,wind power often runs in the maximum power tracking mode.It does not have the ability of primary frequency regulation.And the speed of the wind turbine is not coupled with the grid frequency,the replacement of traditional units by large-scale wind power will greatly reduce the inertial response capability of the system.In addition,due to the strong volatility and randomness of wind power,the response speed and climbing speed of traditional frequency regulation resources are difficult to cope with,which increases the burden of primary frequency regulation in the power system.Battery energy storage has significant advantages such as fast response,flexible control,and two-way adjustment.It has been regarded as one of the effective means to assist the primary frequency regulation of the system.In order to use the technical advantages of energy storage as much as possible to improve the primary frequency regulation effect,it has important engineering value to study the related issues of energy storage in the primary frequency regulation of the power system.This paper first provides information on the state of development of wind power and the state of development of energy conservation,which is involved in the frequency modulation of power systems.It briefly analyzes the extent of the development of wind power and its effect on the frequency regulation of the system.The extent of the development of energy conservation and the status quo of research related to frequency modulation of the energy system are analyzed and the gaps in current research are summarized.Secondly,the impact of different wind power penetrations on static characteristics(such as net load characteristics and power balance)is analyzed,and the dynamic frequency characteristics of the power grid with different wind power penetrations are studied on the basis of the frequency regulation simulation model,which provides a quantitative basis for the determination of frequency modulation requirements.Considering the frequency regulation problem caused by the high penetration of wind power,a method suitable for the configuration of the energy storage capacity of the primary frequency regulation based on the frequency regulation control model of the battery energy storage system is proposed.Then,considering the frequency change characteristics of the dynamic process of primary frequency regulation and the advantages and disadvantages of different frequency regulation control methods,the traditional virtual inertia control and virtual droop control are improved,and a task coefficient model is proposed to dynamically adjust different frequency regulation methods at different stages.The component of the frequency regulation task undertaken will finally form a comprehensive control strategy in which energy storage participates in a frequency modulation.Finally,take a certain regional power grid as an example to verify the effectiveness of the integrated strategy under different working conditions.Finally,in order to improve the adaptability of energy storage output and load development,a second set of control strategies for energy storage to participate in primary frequency modulation is proposed.The frequency regulation process is divided into the frequency regulation stage and the SOC recovery stage.When the frequency crosses the grid frequency modulation dead zone,the energy storage action is mainly aimed at improving the frequency,and the improved virtual droop control method is used to participate in the frequency modulation.When the frequency is in the frequency modulation dead zone,the energy storage takes SOC recovery as the main purpose,and the first layer of fuzzy control is designed,which can dynamically adjusts the SOC recovery benchmark based on the current load status,and then determines the SOC recovery demand based on the SOC benchmark.After that,the second layer of fuzzy control rules is designed to adjust the energy storage output according to the SOC recovery demand and the current frequency deviation.Finally,the simulation verifies the rationality and effectiveness of the proposed control strategy. |
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