基于最优控制原理的电力系统紧急控制及应用

Optimal Control Theory Based Power System Emergency Control and Its Application

基于时域方法仿真得到系统受扰轨迹,并结合实际电网安全稳定控制系统的配置情况和运行要求,给出了暂态稳定下最优紧急控制模型。采用了启发式故障后轨迹相对功角最大值小于门槛值作为暂态稳定约束条件,通过引入变分原理,推导了暂态稳定约束条件对控制量的灵敏度。通过建立线性规划模型,把微分代数方程所描述的电力系统紧急控制转化为以切机切负荷为控制量的最优控制问题。文中提出的暂态稳定紧急控制模型与时域仿真方法具有同等的适应性。广东电网的计算结果表明,文中方法对紧急控制策略灵敏度的确定高效且实用,对保证电网安全稳定运行有重要意义。

Based on the disturbed trajectories from time-domain transient simulation and considering both power system operation requirements and configuration of security and stability control system, an optimal emergency control model under transient stability is developed. The maximum ! relative power angle of post-fault trajectory that is less than the threshold value is taken as the heuristic constraint of transient stability. Using variational principle, the sensitivity of transient stability constraint condition to control variable is derived. By means of building linear programming model, power system emergency control described by differential algebraic equations is changed into the optimal control problem in which the generator tripping and load shedding are taken as control variables. The proposed transient stability emergency control model possesses the same adaptability as that of the time-domain simulation. Calculation results of Guangdong power grid show that the proposed emergency control strategy is efficient and practicable, and is significant for secure and stable operation of power grid.