考虑连锁故障的输电网扩展规划方法

Expansion planning method of transmission network considering cascading failures

为提高电网抵御多重故障的能力,常在输电网规划中嵌入N-k安全网络约束。但该方式未考虑故障间关联性,致使故障场景数量庞大且部分场景与实际不符,可能导致规划方案投资冗余。在计及故障关联性的基础上,提出一种考虑连锁故障的输电网双层扩展规划模型。上层模型以线路投资、运行及切负荷成本之和最小为目标,考虑了故障链约束;下层模型以切负荷最小为目标,对上层模型得到的规划方案进行连锁故障校验。上下层模型以故障链约束为纽带,通过迭代添加新的约束,达到降低求解规模、加快算法收敛的目的。以IEEE RTS-24系统为分析算例,仿真结果表明所提模型能够在抵御连锁故障的同时提升规划方案经济性。

To improve the power grid’s ability to withstand multiple-faults,N-k safety network constraints are often embedded in transmission network planning.The correlation between faults is not considered by the planning method,which leads to a large number of fault scenarios and some of them are inconsistent with the actual situation,moreover leads to redundant investment.A two-level transmission network expansion planning model considering cascading failures is proposed on the basis of considering the fault correlation.The upper model aims at minimizing the sum of line investment,operation and load shedding costs,and considers fault chain constraints.While the lower model aims at minimizing the load shedding,and checks the cascading failure of the planning method obtained from the upper model.The upper and lower models are linked by fault chain constraints,and new constraints are added by iteration to reduce the solution scale and accelerate the convergence of the algorithm.Taking the IEEE RTS-24 system as an analysis example,the simulative results show that the proposed model can resist cascading failures while improve the economy of the planning method.