动态电力系统求取最近鞍点分岔边界的新方法

Closest saddle-node bifurcation boundary in control parameter space

定义系统当前运行点到鞍点分岔点的欧式距离为动态电力系统的电压稳定裕度(负荷裕度),该裕度衡量动态系统稳定运行的负荷增长承受能力。提出了寻求关键特征值的指标,通过该指标,可以给出发生鞍点分岔的初始负荷增长方向,保证系统在到达鞍点分岔点之前不会遭遇其他分岔点。也提出了参数空间下求取动态电力系统发生最近鞍点分岔边界的迭代算法,分析并判断了系统到达该分岔点对应的最危险负荷增长方式。采用IEEE3节点和IEEE57节点仿真系统进行方法验证,仿真结果显示该算法的有效性和良好的收敛性。

An effective iterative method to find the closest Saddle-node bifurcation point in dynamic power system is proposed, and the corresponding load increase pattern, which leads the system to the closest saddle-node bifurcation boundary, is obtained as well. An index for critical eigenvalue selection is also present, through which the initial load increase pattern is determined. The Euclidean distance between the current operating point to the closest saddle-node bifurcation boundary is regarded as the voltage stability margin （or load margin）, which is aimed at assessing the system robustness to system dynamic voltage instabilities. Simulation result obtained both 3-bus and 57-bus test systems, the simulation results illustrate the validity of the proposed method with good convergence.：