大功率缺失下频率最低点估计的低阶仿真模型

作为频率监视的关键参量和频率控制的决策依据，大功率缺失下频率响应过程中的频率最低点需要被准确估计，包括最大频率偏移和频率最低点时间。提出了一种大功率缺失下频率最低点估计的低阶仿真建模方法。通过对调门扰动响应微分进行多项式拟合，描述了调速器的冲激响应特性。基于各机组调速器响应特性的频域变换，建立了系统等效调速器模型。依据大功率缺失下频率下降过程的形态特征，评估了低阶仿真模型的有效性。算例结果表明，所提建模方法能够显著降低频率响应模型阶数，有效提升仿真求解效率，充分保证了频率最低点的计算精度。

Low-order Simulation Model for Frequency Nadir Estimation with High Power Deficit

As the key indicator of frequency monitoring and decision basis of frequency control, the frequency nadir in the process of frequency response with high power deficit including the maximum frequency deviation and the time of frequency nadir should be estimated accurately. A low-order simulation model for frequency nadir estimation with a high power deficit is developed. The impulse response characteristics of governor are described by polynomial fitting the differential response with valve disturbance. The Laplace transformation of the governor response characteristics of each unit is adopted to establish the equivalent governor model of the system. The effectiveness of the low-order simulation model is presented based on the analysis of frequency deviation process with a high power deficit. Case studies show that the proposed model could reduce the order of frequency response model, improve the computation efficiency and achieve a satisfactory computation accuracy of frequency nadir.