基于连续体模型的电力系统机电距离研究

Study on electromechanical distance of power system based on the continuum model

基于电力系统的连续体模型,通过机电距离的概念研究机电扰动在电力系统中的传播特性,可以将大型电力系统划分为研究系统和外部系统,或将外部等值系统划分为多个同调的子区域,这是动态等值必需的前提步骤。定义了一个新的复合机电距离,给出了其物理意义和计算方法。通过New England 10机39节点标准测试系统,用连续体建模和所给出的定义计算出发电机之间的复合机电距离。相应的结果表明:连续体建模和公式的计算结果在该发电机惯性与其它发电机相近时比较接近,而当该发电机惯性与其它发电机相差很大时精度有一定误差。

Based on the continuum model for power system, through the analysis of the propagation characteristics of electromechanical disturbance by utilizing the concept of electromechanical distance, a large-scale power system can be divided into studying system and external system, or the external equivalent system can be divided into several coherent subsystems, which is a necessary premise-step for dynamic equivalence. In this paper, a novel composite electromechanical distance is defined, and its physical meanings and computing method are also presented. Through the New England 10-machine 39-bus test system, the composite electromechanical distances between the corresponding generator buses are computed by taking the continuum modeling approach and the definition presented in this paper. The results show their agreement when the generator inertia is relatively closed to other generators＇. However, the computation precision exists a little error when the generator inertia is rather far from others.