基于概率分布理论和Lyapunov-Krasovskii (L-K)泛函分析方法, 研究一类时滞电力系统的概率分布相关负荷频率稳定性问题. 首先, 考虑模型中通信时滞的概率分布特征, 将安装有PI负荷频率控制器的电力系统转换为一个闭环的随机时滞系统. 其次, 充分利用随机时滞的概率分布信息, 构造合适的增广L-K泛函, 进而使用积分不等式和改进的逆凸组合技术对L-K泛函导数进行估计, 导出电力系统的时滞概率分布相关负荷频率稳定准则. 最后, 通过案例仿真分析表明了所提方法的有效性和优越性.

Based on probability distribution theory and L-K functional methods, the issue of probability-distribution-dependent load frequency stability is investigated for a class of power systems with time-varying delays. Firstly, by considering the probability distribution feature of the communication time-delay in the system modeling, the power systems with PI-based load frequency controller is converted to a closed-loop system with stochastic time-varying delay. Secondly, by fully using the probability distribution information of stochastic time-varying delays, a suitable L-K functional is constructed. Then, by employing the integral inequality and improved reciprocally convex combination technique to estimate the derivative of the L-K functional, some probability-distribution-dependent load frequency stability criteria are derived for the power systems. Finally, some case studies are applied to show the effectiveness and superiority of the design method.