一种改进的时滞电力系统特征值高效计算方法

An improved and highly efficient eigen-analysis method for large time-delayed power system

为高效分析大规模时滞电力系统的小干扰稳定性,基于现有的部分谱离散化时滞电力系统特征值计算方法,提出一种改进的特征值计算方法。针对现有部分谱离散化时滞电力系统特征值计算方法存在矩阵LU分解计算量大和离散化特征方程存在冗余的问题,通过矩阵初等变换对无穷小生成元离散化矩阵的结构进行优化,解决子矩阵奇异的问题,并消除其中的冗余变量。改进方法能够充分利用优化后的无穷小生成元离散化矩阵的稀疏结构,提高大规模时滞电力系统的关键特征值的计算效率。四机两区域系统、山东电网和华北-华中特高压互联电网的计算结果验证了改进方法的准确性和高效性。

To analyze the small signal stability of large time-delayed power systems, an improved eigenvalue-analysis method was presented based on one of the existing partial spectral discretization methods. Two problems in the original method, i.e., massive computational burden in LU factorization and redundant variables in the discretized characteristic equations, were elaborated. The structure of the infinitesimal generator’s discretization matrix was optimized by using elementary permutation. The submatrix of the infinitesimal generator’s discretization matrix became a nonsingular matrix and the redundant variables were eliminated. As a result, the efficiency of the computation of the critical eigenvalues of the time-delayed power system was largely enhanced by fully utilizing the sparse structure of the discretized matrix approximating infinitesimal generator. The accuracy and efficiency of the improved method were validated on the 2-area 4-machine test system, the Shandong power grid and the ultra-high-voltage North China-Central China interconnected power grid.