基于最优负荷削减的小世界电网连锁故障模拟

Optimal Load-Shedding Based Simulation of Cascading Failure in Small-World Power Grid

现有小世界电网连锁故障模型中,故障严重程度的评价指标不能很好地考虑故障后系统运行情况,且计算方法过于简化,为此,提出以最小失负荷百分比作为连锁故障发生后评价故障严重程度的指标,并运用基于直流潮流的负荷削减最优化模型计算最小失负荷量,从而对基于节点电气介数的连锁故障模型的模拟过程进行改进。系统受到攻击后,该方法通过重新调度系统中的发电功率来消除系统约束违限,在无法避免负荷削减时使负荷削减量最小。算例结果验证了该方法的有效性。

As for existing cascading failure models of small-world power grid, the post-failure operating condition has not been appropriately considered in the indices to evaluate the severity of the failure and related computing methods are oversimplified. For this reason, the minimum load shedding percentage is proposed as the index to evaluate the failure severity after the cascading failure occurred, and the amount of minimum load shedding is computed by DC power flow based optimal load shedding model, therefore the simulation process of nodal electric betweenness based cascading failure model is improved. When the disturbance occurs in small-world power grid, the out-of-limit of constraints in the model is eliminated through rescheduling the generator output by dispatching system, and when the load shedding is inevitable the amount of load shedding should be the minimum. The effectiveness of the proposed method is verified by simulation results of IEEE 39-bus system.