基于分段均匀介质模型的非均匀链式电网扰动传播机理

Disturbance Propagation Mechanism in Non-uniform Chained Power Networks Based on Sectionalized Homogeneous Medium Model

揭示扰动传播机理对于提高互联大电网安全水平具有重要作用。机电波理论尝试借助波动力学研究电网机电暂态过程,为研究电网扰动传播开辟了新思路。针对非均匀链式电网的扰动传播问题,提出一种分段均匀介质建模方法。在分析电网与机械波传播介质相似形性的基础上,提出发电机惯量作用域用以确定空间集中式发电机参数的均匀化范围。进一步,导出基于分段均匀介质模型的机电波方程及其解析解,并利用状态传递矩阵证明分段均匀介质模型与电网实际模型的等价性。最后,通过幅值传递矩阵获得解析解系数与分段介质参数的关系。仿真结果验证了所提模型及算法的正确性。

The reveal of disturbance propagation mechanism is of great importance for the security of interconnected power systems. Electromechanical wave theory attempts to explore the power system dynamics from the point of view of wave mechanics and open a new path to the mechanism of disturbance propagation. In this paper, a sectionalized homogeneous medium modeling approach was presented to deal with the disturbance propagation in non-uniform chained power networks. Through analyzing the similarity between power networks and mechanical wave media, the impact scope of the moment of inertia of a generator was introduced in which the generator’s lump mass to be homogenized. Furthermore, the corresponding equation for electromechanical wave propagation in non-uniform chained power networks was established and its analytical solution was derived. The consistency between the proposed model and the practical power network model was proved through state transfer matrix. At last, the relationship between the coefficients of analytical solution and parameters of sectionalized homogeneous model was obtained. Simulation results demonstrated the validity of the proposed model and the analytical solution.