计及工作点偏移的减载风电系统频率响应模型  

System Frequency Response Model of Deloaded Wind Power System Considering Working Point Shifting

作　　者：张龙[1] 孙丹[1] 张旭 年珩[1] ZHANG Long;SUN Dan;ZHANG Xu;NIAN Heng(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电力系统自动化》2024年第16期79-87,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金杰出青年基金资助项目(52325702)。

摘　　要：随着风电并网容量不断升高,利用减载风电机组参与一次调频对保障系统频率稳定性具有重要意义。然而,风机的工作点会随其转速变化而发生偏移,使得风机的实际一次调频贡献小于期望值。为此,文中首先分析了频率故障后风电机组减载功率跟踪控制与综合惯量控制的交互影响,指出了风机工作点偏移导致其调频效果削弱的基本原理。其次,基于风机的转子运动方程推导了风电功频传递函数,建立了计及减载风电机组工作点偏移的系统频率响应模型,并利用最小二乘法对其进行降阶,推导了系统频率最低点的解析式。然后,针对虚拟惯量控制的频率恢复期间引起功率倒流、微分环节放大噪声等缺点,提出利用下垂控制替代综合惯量控制。同时,为使减载风电机组获得期望的调频效果,基于频率最低点和稳态频率指标对风机控制参数进行了修正,提出了两种等效下垂系数的计算方法。最后,在MATLAB/Simulink平台建立了四机两区域模型,验证了所提降阶方法及修正方法的有效性。With the increasing grid-connected capacity of wind power,using deloaded wind turbines(WTs)to participate in the primary frequency regulation is of great significance in safeguarding system frequency stability.However,the working point of the WT shifts with its rotational speed change,which results in the actual capacity of the primary frequency regulation of the WT smaller than the desired value.Therefore,the interaction between the power tracking control of deloaded WTs and the integrated inertia control after a frequency fault is firstly analyzed,and the basic principle that the working point shifting of the WTs leads to the weakening of the frequency regulation effect is pointed out.Secondly,the wind power-frequency transfer function is derived based on the rotor motion equation of the WTs,and the system frequency response(SFR)model is established considering the working point shifting of the deloaded WTs.The least square method is also used to reduce the order of the proposed SFR model,and an analytical formula of the system frequency nadir is deduced.Then,in view of the shortcomings of virtual inertia control,such as power backflow during the frequency recovery and noise amplification in differential links,it is proposed to replace the integrated inertia control with droop control.Meanwhile,in order to make the deloaded WTs obtain the desired frequency regulation effect,the control parameters of the WTs are modified based on the frequency nadir and the steady state frequency indices,and calculation methods for the two equivalent droop coefficients are proposed.Finally,a four-machine two-region model is established on the MATLAB/Simulink platform to verify the effectiveness of the proposed order reduction method and the correction method.

关 键 词：风电机组 系统频率响应模型 降阶 惯量控制 等效下垂系数 

分 类 号：TM614[电气工程—电力系统及自动化]