基于凸组合方法的变时滞电力系统稳定性判据

摘要

In the wide-area environment, the time-delay of control signal generated in the process of transmission and treatment will produce a negative effects that can not be neglected for the stable operation of power system. A stability criterion for power system with time-varying delay based on the method of convex combination is presented. Firstly, through constructing a new type of Lyapunov-Krasovskii functional and proving its positive definiteness, the parameter constraint is relaxed. Secondly, using slack matrices and a convex combination method, the time-varying delay stability criterion, which is less conservative, is derived in terms of linear matrix inequalities. Finally, simulation results indicate that the presented method reduces the conservatism of some existing results.%在广域环境下,控制信号在传输和处理过程中产生的时滞现象会对电力系统的稳定运行产生难以忽略的负面影响.给出了一种基于凸组合方法的变时滞电力系统稳定性判别方法.构造了一种新的Lyapunov- Krasovskii泛函,通过证明其正定性,从而放松了对泛函参数项的约束.使用自由权矩阵和凸组合方法对泛函的导函数进行估计,得到了基于线性矩阵不等式的变时滞电力系统的稳定性判据,降低了现有结论的保守性.通过实例仿真表明,所使用的方法在保守性上优于现存的一些方法.