优化重合闸时刻的策略与效益

Strategy and benefit of optimizing reclosing time

合理整定输电线路重合闸时刻对提高系统的稳定性具有重要意义。提出能量型李雅普诺夫函数值的大小可以作为系统稳定性的指标 ,对比了系统暂态能量值和系统机组摆幅极值之间的关系 ,并由此引出了有利于系统稳定的最佳重合时刻概念。分析了重合闸方式、故障前线路潮流、故障地点对最佳重合时刻的影响 ,制订了在现有的技术条件下针对不同重合闸方式优化重合时刻的策略 ,从而改善了系统在最恶劣故障情况下的稳定性。算例表明优化重合时刻可以大幅提高输电线路暂态稳定极限。

The proper setting of the reclosing time on a transmission line is substantial in improving power system stability.Using the Lyapunov energy function as an index of system stability is proposed.Comparison is made between system transient energy and the maximum generator oscillation angles,and the concept of optimal reclosing time for system stability is then introduced.After analyzing the influences of the reclosing type,the pre fault power flow and the fault position on the optimal reclosing time,different strategies are drawn to optimize the reclosing time according to different reclosing types under current technological conditions,so that system stability against the worst fault can be promoted.Simulations show considerable promotion in the transient stability limit on a transmission line after reclosing time optimization.