随着高比例新能源机组并入电网，电力系统低惯量特性愈加显著，严重影响了系统运行稳定性。为了准确估计新能源电网实际运行状态下的惯量大小，提出了一种基于加权递推最小二乘(WRLS)-受控自回归滑动平均（ARMAX）系统辨识的新能源电力系统等效惯量评估方法。首先，以发电机为对象，建立不同扰动情况下发电机功频响应特性的通用惯量解析模型；其次，以发电机并网母线有功功率和频率扰动作为输入和输出，建立ARMAX模型，考虑到实际电网运行过程中受大、小扰动共同影响，实际测量数据具有异方差性，采用WRLS求解模型中的待辨识参数；然后，提取辨识模型中包含惯量响应的传递函数模型，利用阶跃响应计算惯量源的惯性时间常数，进而计算得到系统等效惯量大小；最后，通过Matlab/Simulink仿真算例验证了所提方法的准确性和实用性。

With the high proportion of new energy units integrated into the power grid, the low inertia characteristic of the power system become more and more significant, which seriously affects the stability of the system operation. In order to accurately estimate the inertia of new energy power grid in actual operation state, a new energy power system equivalent inertia estimation method based on weighted recursive least squares (WRLS) -auto-regressive moving average exogenous(ARMAX) system identification is proposed. Firstly, a general inertia analytical model of generator power-frequency response characteristics under different disturbance conditions is established with the generator as the object. Secondly, the ARMAX model is established by taking the generator grid-connected bus active power and frequency disturbances as inputs and outputs. Considering that the actual power grid operation process is jointly affected by both large and small perturbations, the actual measurement data is heteroscedasticity, and the to-be-identified parameters in the model are solved by WRLS. Then, the transfer function model containing the inertia response in the identification model is extracted, and the inertia time constant of the inertia source is calculated using the step response, and the equivalent inertia of the system is calculated. Finally, the accuracy and practicability of the proposed method are verified by Matlab/Simulink simulation examples.

国家自然科学基金(52367002)；云南省联合基金重点项目(202201BE070001-15)