电力系统小干扰稳定实时风险评估方法

为实时反映当前电力系统小干扰稳定性状况，建立了小干扰稳定性实时风险评估指标，提出了电力系统小干扰稳定实时风险评估方法。评估模型中，在当前运行状态或者关键线路N-1状态下，利用特征值分析方法，以阻尼比0.05作为阈值判断小干扰稳定性;计及输电线路实时故障率计算关键线路N-1状态下小干扰失稳概率。在小干扰失稳后果评估中，利用参与因子筛选调整节点，以控制代价最小化为目标，依据阻尼比灵敏度，迭代计算调整节点控制量，最终协调所有弱阻尼振荡模式控制量，生成综合优化控制方案，计算控制代价作为后果指标;以华中电网某一时间断面的数据为例，验证了该风险评估方法的有效性。

Real-Time Risk Assessment Method of Small Signal Stability of Power Systems

In order to get a real-time reflecting of small signal stability of power systems, a set of indices of real-time risk assessment is given, and a real-time risk assessment method of small signal stability of power system is proposed, in which the damping ratio of 0.05 is chosen as the threshold value to judge small signal stability in a modal analysis under current or N-1 status. In addition, the model for real-time failure rates of power transmission lines is used to calculate small signal instability probability under N-1 status. According to the sensitivity analysis of damping ratios, the controlled quantities of the nodes selected by participation factors, are iteratively calculated with the objective of minimizing control cost. The comprehensive and optimized control scheme is generated by coordinating the controlled quantities of all poorly-damped oscillatory modes and the scheme’s cost is taken as the index to evaluate the consequence. Finally, an example based on the data about Central China Power Grid operation and the local weather in a certain time section was taken to prove the effectiveness of the method mentioned above.