DEEAC的理论证明——四论暂态能量函数直接法

A THEORETICAL PROOF OF DEEAC

对于多机系统中理想的两群失稳模式来说,静态EEAC(SEEAC)提供了暂态稳定的充要条件,这已经逐渐被学术界所接受。本文进一步从理论上证明:在研究首摆稳定性时,只要以足够小的步长,按实际的多机运动轨迹动态地修正EEAC的等值两机系统的功率曲线参数或数值映象,就可以任意逼近积分法的计算精度。这个证明是独立于实际失稳模式和模型的复杂程度的。也就是说在复杂的多群模式或群内同调性很差时,动态EEAC(DEEAC)在多机泰勒级数多步展开精度的含义上仍然是稳定的充要条件。这个结论也适合于复杂模型,从而为DEEAC的进一步发展奠定了坚实的理论基础。

The dynamic equal area criterion (DEEAC) proved theoretically to be both sufficient and necessary conditions for multimachine system stability in this paper, in a sence of multi- step Taylor expansion' s accuracy. This proof is independent of both swing modes and modeling sophistication. Recent achievements are reported on: (1) Safe filtering of cases with CCTs larger than a predefined threshold; (2) reliably finding a start condition for EEAC under unstable cases where no candidate clusters of small size might lose stability; (3) good results for multi -cluster cases; (4) reliable identification of large errors; (5) reliable identification of multi-swing instability. Two kinds of strategies to incorporate detailed models in DEEAC are also suggested with sound reasoning and successful practice.