提出一种基于实时测量的暂态不稳定在线识别方法,其能够用于触发某一类离散紧急控制措施。该方法通过在每一采样时刻观测等值系统故障后轨迹的几何特性,提前判别系统的稳定性,预测系统稳定性的最佳模式在每一采样时刻动态决定并刷新。与以往扩展等面积准则不同,该方法无需计算等值系统的不稳定平衡点,能够克服在静态扩展等面积法则中使用的一些假设限制。使用IEEE50机测试系统算例证明了该方法对于识别复杂区间同步失稳问题的可靠性和有效性。
A method is proposed for the fast and accurate online detection of transient instability based on real-time measurement, which is essential in initiating certain discrete emergency control measures. The method identifies the loss of synchronism early by observing the geometric characteristic of post-fault trajectory of the generalized one-machine equivalent system at each time step. The mode of disturbance that best predicts stability is determined and refreshed at each sampling time step. Unlike the previous extended equal-area criterion (EEAC) method, the proposed method does not require the computation of an unstable equilibrium point and overcomes some limitations because of the assumptions made in the former method using the static EEAC. Examples are given using IEEE 50 generator test system to illustrate reliability and effectiveness in identifying the loss of synchronism under complicated inter-area mode.