暂态功角弱稳定模式辨识及其协调紧急控制策略

Weak Stability Mode Identification of Transient Power Angle and Its Emergency Control Strategy

针对电网发展过程中可能出现的复杂暂态功角失稳现象,提出了用于系统安全稳定分析和控制的暂态功角弱稳定模式的概念及其辨识方法,解析了紧急控制导致弱稳定模式演化为主导失稳模式的机理及其近似必要条件。在理论分析的基础上,提出了基于系统暂态稳定约束转化的紧急控制数学模型,进而设计了基于动态灵敏度指标的启发式协调紧急控制策略计算方法,提升了紧急控制算法对于处理复杂暂态失稳情况的适应性,实现了统筹系统暂态功角多个弱稳定模式的自动协调控制。基于实际电网的算例验证了所提紧急控制负效应机理及策略搜索算法的有效性。

In concern of the instability of the complex transient power angle during the developing process of power grid, a concept of weak stability mode of transient power angle and its identification method are proposed to analyze and control the safety and stability of power system. The mechanism of weak stability mode evolving into dominant instability mode which is caused by the emergency control and its approximate necessary conditions are analyzed. Based on the theoretical analysis, a mathematical model of emergency control based on the transformation of system transient stability constraints is presented. Then a heuristic coordination emergency control strategy based on the dynamic sensitivity index is designed. The adaptability of emergency control algorithm to deal with the complex transient instability is improved and the automatic coordination control method to balance the multiple weak stability modes of power system transient power angle is realized. An example based on the actual grid is used to demonstrate the effetiveness of the presented mechanism of negative effects caused by the emergency control and the presented strategy search algorithm.