电压稳定的概率特征根分析

将传统的小干扰电压稳定性分析法扩展到基于一般性多机系统表达(GMR)技术的概率特征根分析环境。在正态分布的假设下,考虑了由节点功率运行曲线确定的系统多运行方式。某特征根位于复平面左半平面的分布概率表征了该模式的稳定程度,从而由特征根的分布概率和特征根对节点电压的电压失稳模式系数可以判断系统多运行方式时系统电压稳定的薄弱点,同时可为SVC的安装地点提供选择依据。在3机9节点系统上的计算分析表明了该方法的有效性,对目前多馈入交直流混合输电系统中凸现的电压稳定性问题的研究具有一定的意义。

Probabilistic Eigenvalue Analysis for Voltage Stability

The conventional eigenvalue-based small disturbance voltage stability analysis approach is extended to a probabilistic eigenvalue analysis environment based on the generalized multi-machine representation (GMR) technique. The uncertainties considered are system multi-operating conditions derived from the operating profiles of nodal loads and generations with the assumption that all variables having a normal distribution. Since the probability for an eigenvalue being located in the left-hand complex plane indicates its instability degree, the critical nodes for voltage instability for a range of system operating conditions can be estimated using the distribution probabilities of eigenvalues together with the voltage instability mode coefficients of eigenvalues to nodal voltages. In addition, the voltage instability mode coefficients can also be used for SVC location selection. Results of a three-machine system demonstrate the validity of the proposed algorithm. This is of significance for study of voltage stability problem in multi-infeed AC/DC hybrid systems.