On-Line Voltage Stability and Transient Stability Assessment

在线电压稳定性和暂态稳定性评估

• 批准号: 9419458
• 负责人: Adly Girgis
• 金额: $ 8.2万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9419458&HistoricalAwards=false
• 关键词: Line; Voltage; Stability; Transient; Assessment

9419458 Girgis The mail objectives of this research are to develop new methods for on-line voltage stability and transient stability. Load forecasting and the optimal estimation of voltage phasors, generator frequency deviations, and their rate of change will be the basic information for the development. Based on these values, a static index and a transient index will be developed for voltage instability prediction and transient stability detection, respectively. During normal operating conditions, the static index for voltage instability is calculated, and its future values are predicted. Once the system enters a transient state, the transient index, which is for transient instability detection, will be computed. Load flow solutions are considered as the intersections between a space and a space curve. The angle, between the gradient vector of a space surface and the tangent vector of a space curve at an operating point, may be considered as the static index for voltage instability. Its closeness to 90 degrees may indicate the proximity of the operating point to the voltage collapse point. The directional derivatives of the bus injection power in the space surface equation, in the direction of the tangent vectors of the space curves, are possible candidates for weak bus identifications. The proposed indices are available for the voltage phasors and the load flow Jacobian. To predict voltage instability, the voltage instability index may be computed based on the future load and its corresponding load flow solutions. By comparing the voltage instability index for the current operating condition with the index for the predicted load, one may conclude if the system will become close to or away from the voltage collapse point. If the system is in transient state, the unstable mode will be detected primarily. The predicted generator angle difference in the post disturbance period is proposed for this purpose. Once the unstable mode is pred icted, the high dimensional power system model may be aggregated into a low order model. The kinetic energy of this aggregated low order system is proposed as the transient index for transient in stability detection. ***

小行星9419458 本研究的主要目标是开发在线电压稳定和暂态稳定的新方法。 负荷预测和电压相量、发电机频率偏差及其变化率的最优估计将是开发的基本信息。 基于这些值，静态指标和暂态指标将分别用于电压失稳预测和暂态稳定检测。 在正常运行条件下，静态电压失稳指标的计算，并预测其未来值。 一旦系统进入暂态，暂态指标，这是暂态不稳定检测，将被计算。 潮流解被认为是空间和空间曲线的交点。 空间曲面的梯度矢量与空间曲线在某一工作点处的切线矢量之间的夹角可作为电压失稳的静态指标。 其接近90度可以指示操作点接近电压崩溃点。 空间曲面方程中母线注入功率在空间曲线的切向量方向上的方向导数是弱母线识别的可能候选。 所提出的指标可用于电压相量和潮流雅可比矩阵。 为了预测电压不稳定性，可以基于未来负荷及其对应的潮流解来计算电压不稳定性指数。 通过将当前操作条件的电压不稳定性指标与预测负载的指标进行比较，可以得出系统将接近还是远离电压崩溃点的结论。 如果系统处于瞬态，则主要检测出不稳定模式。 为此，提出了在扰动后的预测发电机角差。 一旦预测到不稳定模式，则可以将高维电力系统模型聚合成低阶模型。 提出将该聚集低阶系统的动能作为稳定检测中暂态过程的暂态指标。 ***