在保证小扰动稳定前提下,电力系统可承受的最大时滞称为时滞稳定裕度。给出了一种快速求解时滞稳定裕度的有效方法,它通过在有限区间内追踪一组复矩阵的特征轨迹来确定位于虚轴上的系统关键特征值,进而确定其时滞稳定裕度。该方法不对时滞系统特征方程超越项进行任何形式变换,适用于大规模时滞系统稳定裕度的求解。最后借助单机无穷大系统和WSCC-3机9节点系统,对单一和双时滞情况下的系统时滞稳定裕度进行了分析,验证了该方法的有效性。
Delay margin is defined as the maximum time delay that system can sustain without losing its small signal stability. An effective approach is given to calculate the system delay margin. It determines the system critical eigenvalue and the local delay margin by tracing eigenvalue locus of a complex matrix in a finite interval. The proposed method does not make any transformation to the original characteristic equation. It can be applied to the delay margin analysis in the complicated bulk power systems. SMIB system and WSCC 3-generator-9-bus system are employed to validate its effectiveness.