| Vigorously developing renewable energy is the only way to achieve the "dual carbon" goal.As an important component of renewable energy generation,wind power has developed on a large scale globally due to its mature technology.Currently,China has become the world’s largest and fastest-growing market for wind power generation.The continuous integration of wind power has led to increasingly prominent frequency stability issues in the power system.To ensure the frequency safety of the new power system,it has become inevitable for wind power to actively participate in grid frequency regulation.Domestic and foreign scholars have conducted extensive research on the participation of wind turbines in grid frequency regulation methods,and have gradually applied them to the power grid.With the increase of frequency modulation methods in the system,the complexity of the frequency dynamic characteristics of the power system will also increase.Analyzing the frequency dynamic characteristics of wind power frequency modulation systems is of great significance for analyzing the frequency safety of the power system.In addition,accurately quantifying the frequency modulation capability of wind power under different operating conditions is an important prerequisite for analyzing the frequency dynamic characteristics of the power system after wind power is connected.In response to the above issues,this article conducted the following research:(1)In view of the appropriate improvement of the traditional wind turbine frequency modulation method,a comprehensive frequency modulation method of variable parameter virtual inertia control and constant load shedding pitch angle pitch control is proposed to perform frequency modulation of the system at full wind speed.Based on the above frequency modulation method,the equivalent inertia of variable parameter virtual inertia control,the adjustment coefficient and load shedding ratio of constant load shedding pitch angle pitch control are theoretically constructed,revealing the equivalent inertia of operating conditions on the wind turbine The influence mechanism of frequency modulation capability indicators such as modulation coefficient and load shedding ratio.(2)Based on the equivalent inertia,adjustment coefficient,and traditional System Frequency Response(SFR)model of wind turbine integrated frequency regulation,an improved SFR model considering wind turbine integrated frequency regulation is constructed;Based on this improved SFR model,derive typical frequency dynamic characteristic expressions;Through theoretical analysis,the impact mechanism of operating conditions on the frequency regulation ability of wind turbines and the dynamic behavior of system frequency is revealed;Quantitative analysis was conducted on the impact of factors such as wind power proportion,disturbance size,and initial operating conditions on frequency dynamic characteristics by providing system parameters.(3)Based on the time-domain simulation analysis method,a system with wind power not participating in frequency regulation and adopting comprehensive frequency regulation under different wind power ratios is constructed,and typical frequency spatiotemporal distribution characteristic indicators are statistically analyzed to quantitatively describe the frequency spatiotemporal distribution characteristics;Based on simulation data,the frequency spatiotemporal distribution characteristics of wind power under different wind power ratios were analyzed when it does not participate in frequency modulation and when it participates in frequency modulation;Taking the frequency spatiotemporal distribution characteristics of pure thermal power systems as a reference,the impact of wind power proportion and whether wind power participates in frequency regulation on the frequency spatiotemporal distribution characteristics of the system is compared and analyzed. |
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