暂态能量校正和临界群识别：三论暂态能量函数直接法

当前流行的直接法都采用了基于两群模式的暂态能量函数,认为多机系统的暂态稳定性仅取决于该特定扰动下的两个互补机群间的相对运动,并据此对群内的能量进行了校正。显然,校正中的不一致性将会引入误差。另一方面,群际能量并不是封闭的,它和群内能量之间的互相转换是这类直接法的又一个重要误差源。当同一群内的各机动态响应相差甚远时,这种情况可能变得十分严峻。本文综合分析了暂态能量的校正问题,并介绍了在保持EEAC言简意赅特点的前提下尽量减少此类误差方面所取得的最新成果。 在所有针对群内动能或势能进行校正的直接法中,临界群和余下群的速度或功角对暂态能量的作用是相反的。正确识别临界群是直接法成功的基本前提,而有效地推荐候选的临界群,使需要试探的候选群数目尽量减少则关系到直接法的速度优势。这个长期困扰着直接法的问题最近也被出色地解决了。本文对有关的成果和下一步需要解决的问题进行了讨论。

TRANSIENT ENERGY CORRECTION AND CRITICAL CLUSTER IDENTIFICATION

The prevalent opinion on transient energy functions is based on the assumption of "two-cluster mode" that the energy associated with system separation is only that between a critical cluster and the remaining one, but not that inside each cluster. However, this inter - cluster energy is not a conservative subset, and the transferred energy should be considered according to the critical trajectory. Therefore, proper correction of irrelavant energy is of vitai importance. On the other hand, correct identification of the critical cluster is also a keystone for direct methods with transient energy function. Since this identification task is of the nature of integer programming problems, the way of suggesting candidate critical clusters has been a focus of attention long since. Remarkable progresses in solving the above two problems have been made since the beginning of 1992. This paper uncovers the essence of these problems, reveals the nature of the new developments, and prospects for the future researches.