提出了一种用于分析并列运行的同型多机系统次同步谐振(SSR)稳定性的等效简化方法。该方法基于相似矩阵具有相同特征值的原理,通过构造合适的变换矩阵,将同型N机系统的系统矩阵变换为具有N个子块的分块对角阵,其中N-1个子块完全相同,从而使N机系统的SSR问题可以简化为具有两类结构的N台单机系统来研究,并给出了这两类单机系统的建模方法。采用该等效法可以有效地降低系统维数,且保留了全部的系统特征值信息。理论推导和算例结果都显示了该等效法的正确性和实用性。
An equivalence approach is developed in the paper for analyzing Subsynchronous Resonance (SSR) of identical generators operating in parallel. This method is based on the principle that the similar matrices have the identical eigenvalues. By constructing an appropriate transformation matrix, the state matrix of identical N-machine systems can be similar to a block diagonal matrix with N blocks on the diagonal, in which N-I blocks are identical. Therefore, the SSR analysis of N-machine systems can be conducted based on N single-machine systems of two types. Moreover, the modeling method of the two types of single-machine systems is presented. By this equivalent method, the dimension of multi-machine systems can be reduced efficiently, while no detail of the system's eigenvalue information is lost. The theoretical analysis and calculated results show the validity and the practicability of the full equivalent simplification method.