电力系统频率响应的改进模型与参数估计

近年来,多种因素导致电力系统频率大波动事故时有发生。而目前对电力系统调频能力预估误差较大,有必要采用电力系统频率响应(SFR)模型计算频率的动态响应。文中分析了SFR经典模型的不足之处,据此改进了SFR模型结构,其中考虑了等值调速器的动态特性。进而提出了SFR改进模型的参数估计方法,先直接计算获得部分参数,然后加入保证稳态一致性的参数约束条件,最后辨识获得其余参数。通过仿真算例对频率响应进行了计算,验证了SFR改进模型结构与参数估计方法的有效性。结果表明,SFR改进模型能够有效表征系统频率响应的主要指标,其精度显著高于SFR经典模型。

The improved model and parameter estimation for frequency response of power system

In recent years, many factors lead to the frequency fluctuation accident of power system occurring often. The simulation results of multiple faults show that the estimation error of frequency modulation capability of power system is large at present, so it is necessary to use the power system frequency response (SFR) model to calculate dynamic frequency response. The shortcomings of the classical SFR model are analyzed, and the structure of the SFR model is improved accordingly, in which the dynamic characteristics of the polymer governor are taken into account. Then a parameter tuning method for the improved SFR model is proposed. In this method some parameters are obtained by direct calculation, the parameter equation for keeping steady-state compliance is added, and the other parameters are identified. The structure and parameters of the model are calculated in the simulation example, which verifies the validity of the improved SFR model and parameter tuning. The results indicate that the improved SFR model represent the major characteristics of SFR very well, and its accuracy is much higher than the classical SFR model.