中文摘要：

市场化环境下的电能交易可能引起系统潮流的频繁变化，系统运行不确定性增大，支路过负荷、节点电压越限等故障发生的可能性更大，因此对评估电网功率传输能力提出了更高要求，特别是如何有效评估输电可靠性裕度（TRM），对于电力市场的安全、可靠、经济运行具有重要意义。文中引入至少输电容量的概念，综合考虑了系统中的不确定因素，构建了基于主从递阶决策的TRM双层优化模型，并给出了求解该模型的一种简便、实用的方法。最后通过对IEEE 118节点系统进行数据仿真，说明了该模型的合理性和有效性。

英文摘要：

In a new competition environment, the increased attention to the economic value of transmission interfaces has generated much more interest in accurate and defensible available transfer capability （ATC） computations. However, without considering the severest case in transmission reliability margin （TRM） evaluation, an ATC assessment methodology may not be reasonable. To take the uncertainties of power system operation conditions into account in the computation of TRM, an AC load flow based min-max transfer capacity formulation is proposed by using a bi-level leader-follower decision-making model. A numerical solution to this model is also introduced. For all the participants in an electricity market, the proposed formulation offers more valuable information thari traditional ATC. At last, the 118-bus IEEE RTS is utilized to evaluate the proposed model and the results demonstrate its rationality and validity.