基于广域测量系统响应时间序列的电力系统暂态稳定在线判别

基于实时获取的广域测量信息,提出一种利用功角响应时间序列最大Lyapunov指数指标(largestLyapunov exponent index,LLEI)与角速度偏差相结合的暂态功角稳定判别方法。基于无需系统模型的LLEI估算方法,建立LLEI与角速度偏差的数学关系,并利用相轨迹稳定性动态特征,提出一种基于LLEI与角速度偏差特征的暂态功角稳定判据。该判据无需寻找最优计算时间窗口且所需计算窗口很短,并能给出确切的稳定性判别时间,克服了传统LLEI分析方法的不足,能够准确、快速地判别暂态稳定性。为节省计算时间和计算成本,提出基于最严重受扰机组对的多机电力系统暂态稳定在线判别方案。通过IEEE 10机39节点系统算例,验证了所提方法的准确性及快速性。计算仅利用少量WAMS量测数据,算法简单快速、计算成本低,能够实现在线判别,具有良好的应用前景。

Online Assessment for Transient Stability Based on Response Time Series of Wide-area Measurement System

Based on real-time wide area measurement information, a detection method for power system transient rotor angle stability, combining the largest Lyapunov exponent index(LLEI) of response time series of rotor angel and angular velocity, is proposed. Based on model-free LLEI calculation method, a mathematical equation for LLEI and angular velocity deviation is established. Using stability dynamical characteristics of phase trajectories, a transient rotor angle stability criterion based on LLEI and angular velocity is proposed. The proposed stability criterion does not need predefined optimal time window and long-time LLEI data to identify LLEI final sign and can give exact stability assessment time. To reduce computational cost and calculation time, an online detection scheme for transient stability of multi-machine power system based on critical generator pairs is proposed. Simulation results of IEEE 39-bus system verify accuracy and rapidity of the proposed method. For the algorithm calculating LLEI, only a small amount of measured data from WAMS is needed, and the algorithm is simple and easy with low computation cost. This method can realize online detection, showing excellent application prospects.