含风电虚拟惯性响应的新能源电力系统惯量估计

Inertia estimation of new energy power system with virtual inertia response of wind power

惯量精确估计是分析系统频率安全稳定的前提,而现有方法未能定量评估虚拟惯量对电网等效惯量的影响。鉴于此,文中提出一种含风电虚拟惯性响应的电力系统惯量估计方法。首先推导了含风电虚拟惯性响应的电力系统等效惯量理论表达式;其次利用同步相量测量单元(phasor measurement unit,PMU)获取发电装置节点处的有功-频率数据,然后将发电装置的有功输出功率作为辨识模型输入、频率扰动作为输出,利用受控自回归(controlled autoregressive,CAR)模型以及含有遗忘因子的递推最小二乘(time-varying forgetting factor recursive least squares,TFF-RLS)算法对不同风电渗透率下的全网等效惯量进行评估;最后通过改进的IEEE-10机39节点系统验证所提方法的可行性与适用性。与传统辨识方法相比,文中所提方法估计的惯量精确性有所提高,适用于新能源电力系统时变惯量估计。

The accurate estimation of inertia is the premise of analyzing the security and stability of the system frequency,but the existing methods can not quantitatively evaluate the effect of virtual inertia on the equivalent inertia of the power system.In view of this,an inertia estimation method of power system with virtual inertia response of wind power is proposed.Firstly,the theoretical expression of equivalent inertia of power system including virtual inertia response of wind power is derived.Secondly,the phasor measurement unit(PMU)is used to obtain the active power and frequency data at the node of the power generation device.Thirdly,the active power output of the power generation device is taken as the input of the identification model,and the frequency disturbance is taken as the output.Using controlled autoregressive(CAR)model and time-varying forgetting factor recursive least squares(TFF-RLS)algorithm evaluated the equivalent inertia of the whole network under different wind power proportions.Finally,the feasibility and applicability of the proposed method are verified by an improved IEEE-10-machine 39-node system.Compared with the traditional identification method,the accuracy of the inertia estimation of the proposed method is improved,and it is suitable for the time-varying inertia estimation of the new energy power system.