考虑风电不确定性的电力系统惯量评估方法

Inertia evaluation method of power system considering wind power uncertainty

准确评估电力系统惯量是保障高比例新能源接入后系统安全稳定运行的基础。由于新能源出力具有不确定性,其虚拟惯量响应能力难以量化评估。据此,本文提出一种考虑风电不确定性的电力系统惯量评估方法。首先分析新型电力系统惯量特性,明确系统惯量与频率、功率波动量之间的数学关系;构建考虑新能源不确定性的系统辨识模型,采用鲁棒最小二乘法求解待辨识系统惯量参数;最后通过含风电场的四机两区系统仿真验证了本文方法连续实时评估的有效性及准确性,具有较强的工程适用性。

Accurately evaluating the inertia of the power system is the basis for ensuring the safe and stable operation of the system after a high proportion of new energy is connected.Due to the uncertainty of new energy output,its virtual inertia response capability is difficult to quantitatively evaluate.Accordingly,a power system inertia evaluation method considering the uncertainty of wind power is proposed.Firstly,the inertia characteristics of the new power system are analyzed,and the mathematical relationship between system inertia and frequency and power fluctuation is clarified.Then a system identification model considering the uncertainty of new energy is constructed,and the robust least squares method is used to solve the inertia parameters of the system to be identified.Through the simulation verification of the four-machine two-zone system with wind farms,the continuous real-time evaluation method is effective and accurate,and has strong engineering applicability.