In the steady-state contingency analysis, the traditional Newton-Raphson method suffers from non-convergence issues when solving post-outage power flow problems, which hinders the integrity and accuracy of security assessment. In this paper, we propose a novel robust contingency analysis approach based on holomorphic embedding (HE). The HE-based simulator guarantees convergence if the true power flow solution exists, which is desirable because it avoids the influence of numerical issues and provides a credible security assessment conclusion. In addition, based on the multi-area characteristics of real-world power systems, a partitioned HE (PHE) method is proposed with an interface-based partitioning of HE formulation. The PHE method does not undermine the numerical robustness of HE and significantly reduces the computation burden in large-scale contingency analysis. The PHE method is further enhanced by parallel or distributed computation to become parallel PHE (P${}^\mathrm{2}$HE). Tests on a 458-bus system, a synthetic 419-bus system and a large-scale 21447-bus system demonstrate the advantages of the proposed methods in robustness and efficiency.
翻译:在稳定状态应急分析中,传统的牛顿-拉夫森方法在解决断电后电流问题时遇到非趋同性问题,这妨碍了安全评估的完整性和准确性。在本文件中,我们提出基于全局嵌入(HE)的新颖强健的应急分析方法。基于HE的模拟器保证,如果真正的电流解决方案存在,那么,这种模拟器就能保证趋同,因为这是可取的,因为它避免了数字问题的影响,并提供了可信的安全评估结论。此外,根据真实世界电力系统的多区域特点,还提出了基于对HE的配方进行界面分隔的HE(HE)方法。PHE方法不会破坏HE的数字稳健性,并大大减轻大规模应急分析中的计算负担。PHE方法通过平行或分散的计算得到进一步的增强,成为平行的PHE(P$ ⁇ mathrm{2}HE)。对458-bus系统、合成419-bus系统和大型244-bus系统进行了测试,显示了拟议方法在稳健和效率方面的优点。