适用于机电波传播的电网框架结构模型

A Structural Frame Model of Power Networks Suitable for Propagation of Electromechanical Waves

传统机电波理论将实际电网建模为整个二维空间的连续体模型,将机电波处理为二维平面波。这与实际电力系统情况不完全相符,因此不能真实反映实际电网中机电波传播的特性及现象。为此提出一种全新的由一维均匀参数段按照电网拓扑关系构建的电网框架结构模型。首先分析了实际电网中机电波传播过程的特征,提出电网边界的无反射性、扰动传播距离与地理距离的非一致性以及电网介质的分层特性。在此基础上,将一维链式电网中发电机转动惯量作用域的概念推广到实际电网,提出沿传播路径逐级对称分布转动惯量的等效化处理方法,从而构建了具有分段均匀参数特征的电网空间框架结构模型。进一步采用状态传递矩阵证明了转动惯量等效处理方法的正确性。最后,在PSD-BPA软件中进行IEEE 14节点系统仿真,验证了所建模型与实际电网模型的等效性。

According to traditional electromechanical wave theory, actual power grid is modeled as a non-individual body and the electromechanical wave is regarded as a two-dimensional plane wave, such a processing mode does not completely confirm to the situation of actual power grids, so such model cannot truthfully reflect the characteristics and phenomena of electromechanical wave propagating in actual power grids. For this reason, a brand new structural frame model of power grid, which is composed of one-dimensional segments with uniform parameters connected according to the topology of power networks, is proposed. Firstly, the features of propagation process of electromechanical waves in actual power grid are analyzed, and the unreflecting performance of power grid boundary, the nonuniformity between distance of disturbance propagation and geographical distance and the hierarchical feature of power grid medium are put forward. On this basis, the concept of the impact scope of generator moment of inertia in one-dimensional chained power grid is extended to actual power grid and an equivalent processing method, in which the moment of inertia is symmetrically step-by-step distributed along the propagation path, is proposed, thus a power grid spatial structural frame model with uniform parameters within each segment is constructed. Furthermore, the correctness of equivalent processing method of rotational inertia is confirmed by state transition matrix. Finally, the simulation of IEEE 14-bus system is performed by PSD-BPA software to validate the equivalence between the built model and actual power grid model.